Separators for three-dimensional batteries

ABSTRACT

An electrode structure for use in an energy storage device, the electrode structure comprising a population of electrodes, a population of counter-electrodes and an electrically insulating material layer separating members of the electrode population from members of the counter-electrode population, each member of the electrode population having a longitudinal axis A E  that is surrounded by the electrically insulating separator layer.

FIELD OF THE INVENTION

The present invention generally relates to structures for use in energystorage devices, to energy storage devices incorporating suchstructures, and to methods for producing such structures and energydevices.

BACKGROUND OF THE INVENTION

Rocking chair or insertion secondary batteries are a type of energystorage device in which carrier ions, such as lithium, sodium,potassium, calcium or magnesium ions, move between a positive electrodeand a negative electrode through an electrolyte. The secondary batterymay comprise a single battery cell, or two more battery cells that havebeen electrically coupled to form the battery, with each battery cellcomprising a positive electrode, a negative electrode, a microporousseparator and an electrolyte.

In rocking chair battery cells, both the positive and negativeelectrodes comprise materials into which a carrier ion inserts andextracts. As a cell is discharged, carrier ions are extracted from thenegative electrode and inserted into the positive electrode. As a cellis charged, the reverse process occurs: the carrier ion is extractedfrom the positive and inserted into the negative electrode.

FIG. 1 shows a cross sectional view of an electrochemical stack of anexisting energy storage device, such as a non-aqueous, lithium-ionbattery. The electrochemical stack 1 includes a positive electrodecurrent collector 12, on top of which a positive electrode activematerial layer 13 is assembled. This layer is covered by a microporousseparator 14, over which an assembly of a negative electrode currentcollector 15 and a negative electrode active material layer 16 areplaced. This stack is sometimes covered with another separator layer(not shown) above the negative electrode current collector 15, rolledand stuffed into a can, and filled with a non-aqueous electrolyte toassemble a secondary battery.

The positive and negative electrode current collectors pool electriccurrent from the respective active electrochemical electrodes and enabletransfer of the current to the environment outside the battery. Aportion of a negative electrode current collector is in physical contactwith the negative electrode active material while a portion of apositive electrode current collector is in physical contact with thepositive electrode active material. The current collectors do notparticipate in the electrochemical reaction and are therefore restrictedto materials that are electrochemically stable in the respectiveelectrochemical potential ranges for the anode and cathode.

To bring current from the current collectors to the environment outsidethe battery, the negative electrode and positive electrode currentcollectors are typically each connected to an electrode bus, tab, tag,package feed-through or housing feed-through, typically collectivelyreferred to as contacts. One end of a contact is connected to one ormore current collectors while the other end passes through the batterypackaging for electrical connection to the environment outside thebattery. The negative electrode contact is connected to the negativeelectrode current collectors and the positive electrode contact isconnected to the positive electrode current collectors by welding,crimping, or ultrasonic bonding or is glued in place with anelectrically conductive glue.

Conventional wound batteries (see, e.g., U.S. Pat. Nos. 6,090,505 and6,235,427) typically have electrode materials (active materials, binder,conductivity aid) coated onto a single foil and compressed prior to cellassembly. The foil onto which the electrode is coated onto is typicallypart of the current collection path. In single jellyroll batteries suchas the 18650 or prismatic cells, the current collector foil isultrasonically welded to electrode buses, tabs, tags etc., that carrythe current from the active materials, through the current collectorfoils and the tabs, to the outside of the battery. Depending on thedesign, there may be tabs in multiple places along a single jellyroll,or along one place in one or both ends of the current collector foil.Conventional stacked battery pouch cells have multiple plates (or foils)of active material with areas on top of each foil that are subsequentlygathered and welded together to a tab; which then carries the current tothe outside of the battery pouch (see, e.g., U.S. Patent Publication No.2005/0008939).

Referring again to FIG. 1, during a charging process, lithium leaves thepositive electrode cathode layer 13 and travels through the separator 14as lithium ions into negative electrode active material layer 16.Depending upon the negative electrode active material used, the lithiumions either intercalate (e.g., sit in a matrix of the negative electrodeactive material without forming an alloy) or form an alloy. During adischarge process, the lithium leaves negative electrode active materiallayer 16, travels through the separator 14 and enters positive electrodeactive material layer 13. The current conductors conduct electrons fromthe battery contacts (not shown) to the electrodes or vice versa.

Battery separators are used to separate the anode and cathode duringassembly and battery operations. Separators for existing lithium ionbatteries typically use thin porous insulating materials with high ionpermeability, good mechanical stability, and good chemical compatibilityto the battery chemistries. Structurally, the separator should havesufficient porosity to absorb liquid electrolyte for the high ionicconductivity. It mostly is a microporous layer consisting of either apolymeric membrane or a non-woven fabric mat.

Existing energy storage devices, such as batteries, fuel cells, andelectrochemical capacitors, typically have two-dimensional laminararchitectures (e.g., planar or spiral-wound laminates) as illustrated inFIG. 1 with a surface area of each laminate being roughly equal to itsgeometrical footprint (ignoring porosity and surface roughness).

Three-dimensional batteries have been proposed in the literature as waysto improve battery capacity and active material utilization. It has beenproposed that a three-dimensional architecture may be used to providehigher surface area and higher energy as compared to a two dimensional,laminar battery architecture. There is a benefit to making athree-dimensional energy storage device due to the increased amount ofenergy that may be obtained out of a small geometric area. See, e.g.,Rust et al., WO2008/089110 and Long et. al, “Three-Dimensional BatteryArchitectures,” Chemical Reviews, (2004), 104, 4463-4492.

Despite the advances made to-date, a need remains for secondarybatteries and other energy storage devices having increased energydensity.

SUMMARY OF THE INVENTION

Among the various aspects of the present invention is the provision ofthree-dimensional structures for use in energy storage devices such asbatteries, fuel cells, and electrochemical capacitors. Advantageously,and in accordance with one aspect of the present invention, theproportion of electrode active material relative to the other componentsof the energy storage device, i.e., the non-active material componentsof the energy storage device may be increased. As a result, energystorage devices comprising three-dimensional structures of the presentinvention may have increased energy density. They may also provide ahigher rate of energy retrieval than two-dimensional energy storagedevices for a specific amount of energy stored, such as by minimizing orreducing transport distances for electron and ion transfer between apositive electrode and negative electrode. These devices may be moresuitable for miniaturization and for applications where a geometricalarea available for a device is limited and/or where energy densityrequirement is higher than what may be achieved with a laminar device.

Briefly, therefore, one aspect of the present invention is an electrodestructure for use in an energy storage device. The electrode structurecomprises a population of electrodes having an electrode active materiallayer and a population of counter-electrodes having a counter-electrodeactive material layer. The population of electrodes is arranged inalternating sequence with the population of counter-electrodes along afirst direction. Each member of the electrode population has a bottom, atop, a length L_(E), a width W_(E), a height H_(E), and a longitudinalaxis A_(E) extending from the bottom to the top of each such member andin a direction that is transverse to the first direction, the lengthL_(E) of each member of the electrode population being measured in thedirection of its longitudinal axis A_(E), the width W_(E) of each memberof the electrode population being measured in the first direction, andthe height H_(E) of each member of the electrode population beingmeasured in a direction that is perpendicular to the longitudinal axisA_(E) of each such member and the first direction. The ratio of L_(E) toeach of W_(E) and H_(E) of each member of the electrode population is atleast 5:1, respectively, and the ratio of H_(E) to W_(E) for each memberof the electrode population is between 0.4:1 and 1000:1, respectively.The longitudinal axis A_(E) of each member of the population ofelectrodes is surrounded by an electrically insulating separator layer,and the electrically insulating separator layer comprises a microporousseparator material layer comprising a particulate material and a binderbetween members of the electrode and counter-electrode populations, themicroporous separator material layer having a void fraction of at least20 vol. %.

Another aspect of the present invention is an electrode stack comprisingat least two electrode structures. Each of the electrode structurescomprises an electrode structure comprises a population of electrodeshaving an electrode active material layer and a population ofcounter-electrodes having a counter-electrode active material layer. Thepopulation of electrodes is arranged in alternating sequence with thepopulation of counter-electrodes along a first direction. Each member ofthe electrode population has a bottom, a top, a length L_(E), a widthW_(E), a height H_(E), and a longitudinal axis A_(E) extending from thebottom to the top of each such member and in a direction that istransverse to the first direction, the length L_(E) of each member ofthe electrode population being measured in the direction of itslongitudinal axis A_(E), the width W_(E) of each member of the electrodepopulation being measured in the first direction, and the height H_(E)of each member of the electrode population being measured in a directionthat is perpendicular to the longitudinal axis A_(E) of each such memberand the first direction. The ratio of L_(E) to each of W_(E) and H_(E)of each member of the electrode population is at least 5:1,respectively, and the ratio of H_(E) to W_(E) for each member of theelectrode population is between 0.4:1 and 1000:1, respectively. Thelongitudinal axis A_(E) of each member of the population of electrodesis surrounded by an electrically insulating separator layer, and theelectrically insulating separator layer comprises a microporousseparator material layer comprising a particulate material and a binderbetween members of the electrode and counter-electrode populations, themicroporous separator material layer having a void fraction of at least20 vol. %.

Another aspect of the present invention is a secondary batterycomprising a battery enclosure, a non-aqueous electrolyte and anelectrode structure. The electrode structure comprises a population ofelectrodes having an electrode active material layer and a population ofcounter-electrodes having a counter-electrode active material layer. Thepopulation of electrodes is arranged in alternating sequence with thepopulation of counter-electrodes along a first direction. Each member ofthe electrode population has a bottom, a top, a length L_(E), a widthW_(E), a height H_(E), and a longitudinal axis A_(E) extending from thebottom to the top of each such member and in a direction that istransverse to the first direction, the length L_(E) of each member ofthe electrode population being measured in the direction of itslongitudinal axis A_(E), the width W_(E) of each member of the electrodepopulation being measured in the first direction, and the height H_(E)of each member of the electrode population being measured in a directionthat is perpendicular to the longitudinal axis A_(E) of each such memberand the first direction. The ratio of L_(E) to each of W_(E) and H_(E)of each member of the electrode population is at least 5:1,respectively, and the ratio of H_(E) to W_(E) for each member of theelectrode population is between 0.4:1 and 1000:1, respectively. Thelongitudinal axis A_(E) of each member of the population of electrodesis surrounded by an electrically insulating separator layer, and theelectrically insulating separator layer comprises a microporousseparator material layer comprising a particulate material and a binderbetween members of the electrode and counter-electrode populations, themicroporous separator material layer having a void fraction of at least20 vol. %.

Other objects and features will be in part apparent and in part pointedout hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-section of a cell of an electrochemical stack of atypical, prior art, two-dimensional energy storage device such as alithium ion battery.

FIG. 2 is a perspective view of one embodiment of an electrode structureof the present invention with parts broken away to show internalconstruction;

FIG. 3 is a fragmentary cross-section of the electrode structure of FIG.2 taken in the plane containing the line 3-3.

FIG. 4 is a fragmentary perspective view of a subassembly of theelectrode structure of FIG. 2;

FIG. 5 is a top plan view of a subassembly of the electrode structure ofFIG. 4 taken along line 5.

FIG. 6 is a top plan view of a subassembly of the electrode structure ofFIG. 4 taken along line 6.

FIG. 7 is a cross-section of a subassembly of the electrode structuretaken in the plane containing line 7-7 of FIG. 5.

FIG. 8 is a cross-section of a subassembly of the electrode structuretaken in the plane containing line 8-8 of FIG. 6.

FIG. 9 is a fragmentary perspective view of a subassembly of theelectrode structure of FIG. 2 with parts broken away to show internalconstruction.

FIG. 10 is an exploded view of a three-dimensional secondary battery ofthe present invention.

FIG. 11 is a fragmentary perspective view of the assembledthree-dimensional secondary battery of FIG. 10.

FIG. 12 is a cross-section of an alternative embodiment of the electrodestructure of FIG. 2 taken in the plane containing the line 3-3.

FIG. 13 is a cross-section of an alternative embodiment of the electrodestructure of FIG. 2 taken in the plane containing the line 3-3.

FIG. 14 is a cross-section of an alternative embodiment of the electrodestructure of FIG. 2 taken in the plane containing the line 3-3.

FIG. 15 is a cross-section of an alternative embodiment of the electrodestructure of FIG. 2 taken in the plane containing the line 3-3.

FIG. 16 is a cross-section of an alternative embodiment of the electrodestructure of FIG. 2 taken in the plane containing the line 3-3.

FIG. 17 is a cross-section of an alternative embodiment of the electrodestructure of FIG. 2 taken in the plane containing the line 3-3.

FIG. 18 is a cross-section of an alternative embodiment of the electrodestructure of FIG. 2 taken in the plane containing the line 3-3.

FIG. 19 is a fragmentary perspective view of an alternative embodimentof a subassembly of the electrode structure of FIG. 2 with parts brokenaway to show internal construction.

FIG. 20 is a cross-section of an alternative embodiment of the electrodestructure of FIG. 2 taken in the plane containing the line 3-3.

FIG. 21 is of a cross-section of an alternative embodiment of theelectrode structure of FIG. 2 taken in the plane containing the line3-3.

FIG. 22 is an alternative embodiment of a cross-section of the electrodestructure of FIG. 2 taken in the plane containing the line 3-3.

FIG. 23 is a fragmentary perspective view of a subassembly of analternative embodiment of the electrode structure of FIG. 4 taken alongline 5 with parts broken away to show internal construction.

FIG. 24 is a fragmentary perspective view of a subassembly of analternative embodiment of the electrode structure of FIG. 4 taken alongline 6 with parts broken away to show internal construction.

FIGS. 25A-E are cross-sections of alternative embodiments of anelectrode (positive electrode or negative electrode) of the presentinvention.

FIG. 26 is a cross-section of an alternative embodiment of an electrodestack of the present invention.

FIG. 27 is a cross-section of an alternative embodiment of an electrodestack of the present invention.

Corresponding reference characters indicate corresponding partsthroughout the drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Among the various aspects of the present invention may be notedthree-dimensional structures offering particular advantages whenincorporated into energy storage devices such as batteries, capacitors,and fuel cells. For example, such structures may be incorporated intosecondary batteries in which the positive electrode, negative electrode,and/or a separator are non-laminar in nature. In one preferred exemplaryembodiment, such structures are incorporated into secondary batteries inwhich carrier ions (selected, for example, from lithium, sodium,potassium, calcium and magnesium ions) move between the positive andnegative electrodes.

In general, the three-dimensional structure comprises a population ofelectrodes, a population of counter-electrodes and a separator materialto electrically isolate members of the electrode population from membersof the counter-electrode population. The populations of electrodes andcounter-electrodes are arranged in an alternating sequence, withsubstantially each member of the electrode population being between twomembers of the counter-electrode population and substantially eachmember of the counter-electrode population being between two members ofthe electrode population. For example, with the exception of the firstand last electrode or counter-electrode in the alternating series, inone embodiment each electrode in the alternating series is between twocounter-electrodes and each counter-electrode in the series is betweentwo electrodes.

In one embodiment, members of the electrode population comprise anelectrode active material layer, an electrode current collector and anelectrode backbone that supports the electrode active material layer andthe electrode current collector. Similarly, in one embodiment, membersof the counter-electrode population comprise a counter-electrode activematerial layer, a counter-electrode current collector and acounter-electrode backbone that supports the counter-electrode activematerial layer and the counter-electrode current collector.

Each member of the electrode population has a bottom, a top, and alongitudinal axis (A_(E)) extending from the bottom to the top thereofand in a direction generally perpendicular to the direction in which thealternating sequence of electrodes and counter-electrodes progresses.Additionally, each member of the electrode population has a length(L_(E)) measured along the longitudinal axis (A_(E)), a width (W_(E))measured in the direction in which the alternating sequence ofelectrodes and counter-electrodes progresses, and a height (H_(E))measured in a direction that is perpendicular to each of the directionsof measurement of the length (L_(E)) and the width (W_(E)). Each memberof the electrode population also has a perimeter (P_(E)) thatcorresponds to the sum of the length(s) of the side(s) of a projectionof the electrode in a plane that is normal to its longitudinal axis.

The length (L_(E)) of the members of the electrode population will varydepending upon the energy storage device and its intended use. Ingeneral, however, the members of the electrode population will typicallyhave a length (L_(E)) in the range of about 5 mm to about 500 mm. Forexample, in one such embodiment, the members of the electrode populationhave a length (L_(E)) of about 10 mm to about 250 mm. By way of furtherexample, in one such embodiment the members of the electrode populationhave a length (L_(E)) of about 25 mm to about 100 mm.

The width (W_(E)) of the members of the electrode population will alsovary depending upon the energy storage device and its intended use. Ingeneral, however, each member of the electrode population will typicallyhave a width (W_(E)) within the range of about 0.01 mm to 2.5 mm. Forexample, in one embodiment, the width (W_(E)) of each member of theelectrode population will be in the range of about 0.025 mm to about 2mm. By way of further example, in one embodiment, the width (W_(E)) ofeach member of the electrode population will be in the range of about0.05 mm to about 1 mm.

The height (H_(E)) of the members of the electrode population will alsovary depending upon the energy storage device and its intended use. Ingeneral, however, members of the electrode population will typicallyhave a height (H_(E)) within the range of about 0.05 mm to about 10 mm.For example, in one embodiment, the height (H_(E)) of each member of theelectrode population will be in the range of about 0.05 mm to about 5mm. By way of further example, in one embodiment, the height (H_(E)) ofeach member of the electrode population will be in the range of about0.1 mm to about 1 mm.

The perimeter (P_(E)) of the members of the electrode population willsimilarly vary depending upon the energy storage device and its intendeduse. In general, however, members of the electrode population willtypically have a perimeter (P_(E)) within the range of about 0.025 mm toabout 25 mm. For example, in one embodiment, the perimeter (P_(E)) ofeach member of the electrode population will be in the range of about0.1 mm to about 15 mm. By way of further example, in one embodiment, theperimeter (P_(E)) of each member of the electrode population will be inthe range of about 0.5 mm to about 10 mm.

In general, members of the electrode population have a length (L_(E))that is substantially greater than each of its width (W_(E)) and itsheight (H_(E)). For example, in one embodiment, the ratio of L_(E) toeach of W_(E) and H_(E) is at least 5:1, respectively (that is, theratio of L_(E) to W_(E) is at least 5:1, respectively and the ratio ofL_(E) to H_(E) is at least 5:1, respectively), for each member of theelectrode population. By way of further example, in one embodiment theratio of L_(E) to each of W_(E) and H_(E) is at least 10:1. By way offurther example, in one embodiment, the ratio of L_(E) to each of W_(E)and H_(E) is at least 15:1. By way of further example, in oneembodiment, the ratio of L_(E) to each of W_(E) and H_(E) is at least20:1, for each member of the electrode population.

Additionally, it is generally preferred that members of the electrodepopulation have a length (L_(E)) that is substantially greater than itsperimeter (P_(E)); for example, in one embodiment, the ratio of L_(E) toP_(E) is at least 1.25:1, respectively, for each member of the electrodepopulation. By way of further example, in one embodiment the ratio ofL_(E) to P_(E) is at least 2.5:1, respectively, for each member of theelectrode population. By way of further example, in one embodiment, theratio of L_(E) to P_(E) is at least 3.75:1, respectively, for eachmember of the electrode population.

In one embodiment, the ratio of the height (H_(E)) to the width (W_(E))of the members of the electrode population is at least 0.4:1,respectively. For example, in one embodiment, the ratio of H_(E) toW_(E) will be at least 2:1, respectively, for each member of theelectrode population. By way of further example, in one embodiment theratio of H_(E) to W_(E) will be at least 10:1, respectively. By way offurther example, in one embodiment the ratio of H_(E) to W_(E) will beat least 20:1, respectively. Typically, however, the ratio of H_(E) toW_(E) will generally be less than 1,000:1, respectively. For example, inone embodiment the ratio of H_(E) to W_(E) will be less than 500:1,respectively. By way of further example, in one embodiment the ratio ofH_(E) to W_(E) will be less than 100:1, respectively. By way of furtherexample, in one embodiment the ratio of H_(E) to W_(E) will be less than10:1, respectively. By way of further example, in one embodiment theratio of H_(E) to W_(E) will be in the range of about 2:1 to about100:1, respectively, for each member of the electrode population.

Each member of the counter-electrode population has a bottom, a top, anda longitudinal axis (A_(CE)) extending from the bottom to the topthereof and in a direction generally perpendicular to the direction inwhich the alternating sequence of electrodes and counter-electrodesprogresses. Additionally, each member of the counter-electrodepopulation has a length (L_(CE)) measured along the longitudinal axis(A_(CE)), a width (W_(CE)) measured in the direction in which thealternating sequence of electrodes and counter-electrodes progresses,and a height (H_(CE)) measured in a direction that is perpendicular toeach of the directions of measurement of the length (L_(CE)) and thewidth (W_(CE)). Each member of the counter-electrode population also hasa perimeter (P_(CE)) that corresponds to the sum of the length(s) of theside(s) of a projection of the counter-electrode in a plane that isnormal to its longitudinal axis.

The length (L_(CE)) of the members of the counter-electrode populationwill vary depending upon the energy storage device and its intended use.In general, however, each member of the counter-electrode populationwill typically have a length (L_(CE)) in the range of about 5 mm toabout 500 mm. For example, in one such embodiment, each member of thecounter-electrode population has a length (L_(CE)) of about 10 mm toabout 250 mm. By way of further example, in one such embodiment eachmember of the counter-electrode population has a length (L_(CE)) ofabout 25 mm to about 100 mm.

The width (W_(CE)) of the members of the counter-electrode populationwill also vary depending upon the energy storage device and its intendeduse. In general, however, members of the counter-electrode populationwill typically have a width (W_(CE)) within the range of about 0.01 mmto 2.5 mm. For example, in one embodiment, the width (W_(CE)) of eachmember of the counter-electrode population will be in the range of about0.025 mm to about 2 mm. By way of further example, in one embodiment,the width (W_(CE)) of each member of the counter-electrode populationwill be in the range of about 0.05 mm to about 1 mm.

The height (H_(CE)) of the members of the counter-electrode populationwill also vary depending upon the energy storage device and its intendeduse. In general, however, members of the counter-electrode populationwill typically have a height (H_(CE)) within the range of about 0.05 mmto about 10 mm. For example, in one embodiment, the height (H_(CE)) ofeach member of the counter-electrode population will be in the range ofabout 0.05 mm to about 5 mm. By way of further example, in oneembodiment, the height (H_(CE)) of each member of the counter-electrodepopulation will be in the range of about 0.1 mm to about 1 mm.

The perimeter (P_(CE)) of the members of the counter-electrodepopulation will also vary depending upon the energy storage device andits intended use. In general, however, members of the counter-electrodepopulation will typically have a perimeter (P_(CE)) within the range ofabout 0.025 mm to about 25 mm. For example, in one embodiment, theperimeter (P_(CE)) of each member of the counter-electrode populationwill be in the range of about 0.1 mm to about 15 mm. By way of furtherexample, in one embodiment, the perimeter (P_(CE)) of each member of thecounter-electrode population will be in the range of about 0.5 mm toabout 10 mm.

In general, each member of the counter-electrode population has a length(L_(CE)) that is substantially greater than width (W_(CE)) andsubstantially greater than its height (H_(CE)). For example, in oneembodiment, the ratio of L_(CE) to each of W_(CE) and H_(CE) is at least5:1, respectively (that is, the ratio of L_(CE) to W_(CE) is at least5:1, respectively and the ratio of L_(CE) to H_(CE) is at least 5:1,respectively), for each member of the counter-electrode population. Byway of further example, in one embodiment the ratio of L_(CE) to each ofW_(CE) and H_(CE) is at least 10:1 for each member of thecounter-electrode population. By way of further example, in oneembodiment, the ratio of L_(CE) to each of W_(CE) and H_(CE) is at least15:1 for each member of the counter-electrode population. By way offurther example, in one embodiment, the ratio of L_(CE) to each ofW_(CE) and H_(CE) is at least 20:1 for each member of thecounter-electrode population.

Additionally, it is generally preferred that members of thecounter-electrode population have a length (L_(CE)) that issubstantially greater than its perimeter (P_(CE)); for example, in oneembodiment, the ratio of L_(CE) to P_(CE) is at least 1.25:1,respectively, for each member of the counter-electrode population. Byway of further example, in one embodiment the ratio of L_(CE) to P_(CE)is at least 2.5:1, respectively, for each member of thecounter-electrode population. By way of further example, in oneembodiment, the ratio of L_(CE) to P_(CE) is at least 3.75:1,respectively, for each member of the counter-electrode population.

In one embodiment, the ratio of the height (H_(CE)) to the width(W_(CE)) of the members of the counter-electrode population is at least0.4:1, respectively. For example, in one embodiment, the ratio of H_(CE)to W_(CE) will be at least 2:1, respectively, for each member of thecounter-electrode population. By way of further example, in oneembodiment the ratio of H_(CE) to W_(CE) will be at least 10:1,respectively, for each member of the counter-electrode population. Byway of further example, in one embodiment the ratio of H_(CE) to W_(CE)will be at least 20:1, respectively, for each member of thecounter-electrode population. Typically, however, the ratio of H_(CE) toW_(CE) will generally be less than 1,000:1, respectively, for eachmember of the electrode population. For example, in one embodiment theratio of H_(CE) to W_(CE) will be less than 500:1, respectively, foreach member of the counter-electrode population. By way of furtherexample, in one embodiment the ratio of H_(CE) to W_(CE) will be lessthan 100:1, respectively. By way of further example, in one embodimentthe ratio of H_(CE) to W_(CE) will be less than 10:1, respectively. Byway of further example, in one embodiment the ratio of H_(CE) to W_(CE)will be in the range of about 2:1 to about 100:1, respectively, for eachmember of the counter-electrode population.

To electrically isolate members of the population of electrodes from thepopulation of counter-electrodes, (i) members of the electrodepopulation are surrounded by an electrically insulating separatormaterial layer along their longitudinal axes (A_(E)), (ii) members ofthe counter-electrode population are surrounded by a layer of anelectrically insulating separator material along their longitudinal axes(A_(CE)), or (iii) members of the electrode population and members ofthe counter-electrode population are each surrounded by a layer of anelectrically insulating material along their respective longitudinalaxes. For example, in one embodiment the longitudinal axes (A_(E)) ofeach member of the population of electrodes is surrounded by a layer ofan electrically insulating material. By way of further example, in oneembodiment the longitudinal axes (A_(CE)) of each member of thepopulation of counter-electrodes is surrounded by a layer of anelectrically insulating material. By way of further example, in oneembodiment the longitudinal axes (A_(CE)) of each member of thepopulation of electrodes and the longitudinal axes (A_(CE)) of eachmember of the population of counter-electrodes are surrounded by a layerof an electrically insulating material.

In one embodiment, the electrically insulating material layer will havea thickness of at least about 5 micrometers. In general, however, theelectrically insulating material layer will have a thickness (at leastin those areas separating a member of the population of electrodes fromthe nearest member of the population of counter-electrodes) that doesnot exceed about 100 micrometers. For example, in certain embodimentsthe electrically insulating material layer will have a thickness (atleast in those areas separating a member of the population of electrodesfrom the nearest member of the population of counter-electrodes) in therange of about 5 to about 50 micrometers. By way of further example, incertain embodiments the electrically insulating material layer will havea thickness (at least in those areas separating a member of thepopulation of electrodes from the nearest member of the population ofcounter-electrodes) in the range of about 10 to about 35 micrometers. Byway of further example, in certain embodiments the electricallyinsulating material layer will have a thickness (at least in those areasseparating a member of the population of electrodes from the nearestmember of the population of counter-electrodes) in the range of about 15to about 30 micrometers.

To permit carrier ion exchange between members of the electrodepopulation and members of the counter-electrode population during acharging or discharging operation, the electrically insulating materiallayer separating the electrode active material layers of members of theelectrode population and the counter-electrode active material layers ofmembers of the counter-electrode population comprises a microporousseparator material. In one embodiment, for example, and ignoring theporosity of the microporous separator material, the microporousseparator material constitutes at least 70 vol % of the electricallyinsulating separator material layer between members of the electrodepopulation and members of the counter-electrode population. By way offurther example, in one embodiment and ignoring the porosity of themicroporous separator material, the microporous separator materialconstitutes at least 75 vol % of the electrically insulating separatormaterial layer between members of the electrode population and membersof the counter-electrode population. By way of further example, in oneembodiment and ignoring the porosity of the microporous separatormaterial, the microporous separator material constitutes at least 80 vol% of the electrically insulating separator material layer betweenmembers of the electrode population and members of the counter-electrodepopulation. By way of further example, in one embodiment and ignoringthe porosity of the microporous separator material, the microporousseparator material constitutes at least 85 vol % of the electricallyinsulating separator material layer between members of the electrodepopulation and members of the counter-electrode population. By way offurther example, in one embodiment and ignoring the porosity of themicroporous separator material, the microporous separator materialconstitutes at least 90 vol % of the electrically insulating separatormaterial layer between members of the electrode population and membersof the counter-electrode population. By way of further example, in oneembodiment and ignoring the porosity of the microporous separatormaterial, the microporous separator material constitutes at least 95 vol% of the electrically insulating separator material layer betweenmembers of the electrode population and members of the counter-electrodepopulation. By way of further example, in one embodiment and ignoringthe porosity of the microporous separator material, the microporousseparator material constitutes at least 99 vol % of the electricallyinsulating separator material layer between members of the electrodepopulation and members of the counter-electrode population.

In one embodiment, the microporous separator material comprises aparticulate material and a binder, and has a porosity (void fraction) ofat least about 20 vol. % The pores of the microporous separator materialwill have a diameter of at least 50 Å and will typically fall within therange of about 250 to 2,500 Å. The microporous separator material willtypically have a porosity of less than about 75%. In one embodiment, themicroporous separator material has a porosity (void fraction) of atleast about 25 vol. %. In one embodiment, the microporous separatormaterial will have a porosity of about 35-55%.

The binder for the microporous separator material may be selected from awide range of inorganic or polymeric materials. For example, in oneembodiment the binder is an organic material selected from the groupconsisting of silicates, phosphates, aluminates, aluminosilicates, andhydroxides such as magnesium hydroxide, calcium hydroxide etc. Forexample, in one embodiment the binder is a fluoropolymer derived frommonomers containing vinylidene fluoride, hexafluoropropylene,tetrafluoropropene, and the like. In another embodiment, the binder is apolyolefin such as polyethylene, polypropylene, or polybutene, havingany of a range of varying molecular weights and densities. In anotherembodiment, the binder is selected from the group consisting ofethylene-diene-propene terpolymer, polystyrene, polymethyl methacrylate,polyethylene glycol, polyvinyl acetate, polyvinyl butyral, polyacetal,and polyethyleneglycol diacrylate. In another embodiment, the binder isselected from the group consisting of methyl cellulose, carboxymethylcellulose, styrene rubber, butadiene rubber, styrene-butadiene rubber,isoprene rubber, polyacrylamide, polyvinyl ether, polyacrylic acid,polymethacrylic acid, and polyethylene oxide. In another embodiment, thebinder is selected from the group consisting of acrylates, styrenes,epoxies, and silicones. In another embodiment, the binder is a copolymeror blend of two or more of the aforementioned polymers.

The particulate material comprised by the microporous separator materialmay also be selected from a wide range of materials. In general, suchmaterials have a relatively low electronic and ionic conductivity atoperating temperatures and do not corrode under the operating voltagesof the battery electrode or current collector contacting the microporousseparator material. For example, in one embodiment the particulatematerial has a conductivity for carrier ions (e.g., lithium) of lessthan 1×10⁻⁴ S/cm. By way of further example in one embodiment theparticulate material has a conductivity for carrier ions of less than1×10⁻⁵ S/cm. By way of further example in one embodiment the particulatematerial has a conductivity for carrier ions of less than 1×10⁻⁶ S/cm.Exemplary particulate materials include particulate polyethylene,polypropylene, a TiO₂-polymer composite, silica aerogel, fumed silica,silica gel, silica hydrogel, silica xerogel, silica sol, colloidalsilica, alumina, titania, magnesia, kaolin, talc, diatomaceous earth,calcium silicate, aluminum silicate, calcium carbonate, magnesiumcarbonate, or a combination thereof. For example, in one embodiment theparticulate material comprises a particulate oxide or nitride such asTiO₂, SiO₂, Al₂O₃,GeO₂, B₂O₃, Bi₂O₃, BaO, ZnO, ZrO₂, BN, Si₃N₄, Ge₃N₄.See, e.g., P. Arora and J. Zhang, “Battery Separators” Chemical Reviews2004, 104, 4419-4462). In one embodiment, the particulate material willhave an average particle size of about 20 nm to 2 micrometers, moretypically 200 nm to 1.5 micrometers. In one embodiment, the particulatematerial will have an average particle size of about 500 nm to 1micrometer.

In an alternative embodiment, the particulate material comprised by themicroporous separator material may be bound by techniques such assintering, binding, curing etc while maintaining the void fractiondesired for electrolyte ingress to provide the ionic conductivity forthe functioning of the battery.

Microporous separator materials may be deposited, for example, byelectrophoretic deposition of a particulate separator material in whichparticles are coalesced by surface energy such as electrostaticattraction or van der Waals forces, slurry deposition (including spin orspray coating) of a particulate separator material, screen printing, dipcoating, and electrostatic spray deposition. Binders may be included inthe deposition process; for example, the particulate material may beslurry deposited with a dissolved binder that precipitates upon solventevaporation, electrophoretically deposited in the presence of adissolved binder material, or co-electrophoretically deposited with abinder and insulating particles etc. Alternatively, or additionally,binders may be added after the particles are deposited into or onto theelectrode structure; for example, the particulate material may bedispersed in an organic binder solution and dip coated or spray-coated,followed by drying, melting, or cross-linking the binder material toprovide adhesion strength.

In an assembled energy storage device, the microporous separatormaterial is permeated with a non-aqueous electrolyte suitable for use asa secondary battery electrolyte. Typically, the non-aqueous electrolytecomprises a lithium salt dissolved in an organic solvent. Exemplarylithium salts include inorganic lithium salts such as LiClO₄, LiBF₄,LiPF₆, LiAsF₆, LiCl, and LiBr; and organic lithium salts such asLiB(C₆H₅)₄, LiN(SO₂CF₃)₂, LiN(SO₂CF₃)₃, LiNSO₂CF₃, LiNSO₂CF₅,LiNSO₂C₄F₉, LiNSO₂C₅F₁₁, LiNSO₂C₆F₁₃, and LiNSO₂C₇F₁₅. Exemplary organicsolvents to dissolve the lithium salt include cyclic esters, chainesters, cyclic ethers, and chain ethers. Specific examples of the cyclicesters include propylene carbonate, butylene carbonate, γ-butyrolactone,vinylene carbonate, 2-methyl-γ-butyrolactone, acetyl-γ-butyrolactone,and γ-valerolactone. Specific examples of the chain esters includedimethyl carbonate, diethyl carbonate, dibutyl carbonate, dipropylcarbonate, methyl ethyl carbonate, methyl butyl carbonate, methyl propylcarbonate, ethyl butyl carbonate, ethyl propyl carbonate, butyl propylcarbonate, alkyl propionates, dialkyl malonates, and alkyl acetates.Specific examples of the cyclic ethers include tetrahydrofuran,alkyltetrahydrofurans, dialkyltetrahydrofurans, alkoxytetrahydrofurans,dialkoxytetrahydrofurans, 1,3-dioxolane, alkyl-1,3-dioxolanes, and1,4-dioxolane. Specific examples of the chain ethers include1,2-dimethoxyethane, 1,2-diethoxythane, diethyl ether, ethylene glycoldialkyl ethers, diethylene glycol dialkyl ethers, triethylene glycoldialkyl ethers, and tetraethylene glycol dialkyl ethers.

In one embodiment, the population of electrodes is a population ofnegative electrodes and the population of counter-electrodes is apopulation of positive electrodes. In this embodiment, longitudinal axisA_(E), length L_(E), width W_(E), height H_(E) and perimeter P_(E) ofmembers of the electrode population correspond to longitudinal axisA_(NE), length L_(NE), width W_(NE), height H_(NE) and perimeter P_(NE),respectively, of members of the negative electrode population andlongitudinal axis A_(CE), length L_(CE), width W_(CE), height H_(CE) andperimeter P_(CE) of members of the counter-electrode populationcorrespond to longitudinal axis A_(PE), length L_(PE), width W_(PE),height H_(PE), and perimeter P_(PE), respectively, of members of thepositive electrode population.

In an alternative embodiment, the population of electrodes is apopulation of positive electrodes, and the population ofcounter-electrodes is a population of negative electrodes. In thisembodiment, therefore, longitudinal axis A_(E), length L_(E), widthW_(E), height H_(E), and perimeter P_(E) of members of the electrodepopulation correspond to longitudinal axis A_(PE), length L_(PE), widthW_(PE), height H_(PE), and perimeter P_(PE), respectively, of members ofthe positive electrode population and longitudinal axis A_(CE), lengthL_(CE), width W_(CE), height H_(CE) and perimeter P_(CE) of members ofthe counter-electrode population correspond to longitudinal axis A_(NE),length L_(NE), width W_(NE), height H_(NE) and perimeter P_(NE),respectively, of members of the negative electrode population.

Referring now to FIG. 2, and in one embodiment of the present invention,electrode structure 20 comprises population of negative electrodes 21and population of positive electrodes 22. For ease of illustration, thepopulation of negative electrodes includes four members 21 and thepopulation of positive electrodes includes four members 22 in FIG. 2; inpractice, however, the population of negative electrodes and thepopulation of positive electrodes may each comprise a greater or lessernumber of members. For example, in one embodiment the population ofnegative electrodes and the population of positive electrodes comprisedby an electrode structure of the present invention may each include atleast 5 members. By way of further example, in one embodiment thepopulation of negative electrodes and the population of positiveelectrodes each include at least 10 members. By way of further example,in one embodiment the population of negative electrodes and thepopulation of positive electrodes each include at least 50 members. Byway of further example, in one embodiment the population of negativeelectrodes and the population of positive electrodes each include atleast 100 members.

Irrespective of the number of members, members 21 of the population ofnegative electrodes and members 22 of the population of positiveelectrodes are interdigitated and arranged in an alternating seriesproceeding in direction D. As illustrated in FIG. 2, with one exception,each member 21 of the population of negative electrodes is between twomembers 22 of the positive electrode population and, with one exception,each member 22 of the population of positive electrodes is between twomembers 21 of the population of negative electrodes. Stated moregenerally, in one embodiment the positive electrode population and thenegative electrode population each have N members, each of N−1 positiveelectrode population members is between two negative electrodes, each ofN−1 negative electrode population members is between two positiveelectrodes, and N is at least 2. For example, in one embodiment, N is atleast 4 (as illustrated in FIG. 2), at least 5, at least 10, at least25, at least 50 or even at least 100.

In one alternative embodiment, each member 21 of the negative electrodepopulation is between two members 22 of the population of positiveelectrodes such that the interdigitated series begins and ends with apositive electrode 22 and each negative electrode 21 is between twopositive electrodes 22 (e.g., a series of electrodes having thefollowing repeat sequence: positive electrode, negative electrode,positive electrode, negative electrode, positive electrode . . . ) withthe interdigitated series progressing in direction D. For example, inone such embodiment, the negative electrode population has N members,the positive electrode population has N+1 members, each negativeelectrode is between two positive electrodes, and N is at least 5, atleast 10, at least 25, at least 50 or even at least 100.

In another alternative embodiment, for example, each member 22 of thepopulation of positive electrodes is between two members 21 of thepopulation of negative electrodes such that the interdigitated seriesbegins and ends with a negative electrode 21 and each positive electrode22 is between two negative electrodes 21 (e.g., a series of electrodeshaving the following repeat sequence: negative electrode, positiveelectrode, negative electrode, positive electrode, negative electrode .. . ) with the interdigitated series progressing in direction D. In onesuch embodiment, the positive electrode population has N members, thenegative electrode population has N+1 members, each positive electrodeis between two negative electrodes, and N is at least 5, at least 10, atleast 25, at least 50 or even at least 100.

Referring again to FIG. 2, each member 21 of the population of negativeelectrodes is directly connected to and extends from negative electrodebus 23 which pools current from each member 21 of the population ofnegative electrodes. Negative electrode bus 23, in turn, may be used toelectrically connect each member 21 of the population of negativeelectrodes to the negative terminal of an energy storage device (notshown) or to an external energy supply (not shown) or an external energyconsumer (not shown).

Each member 22 of the population of positive electrodes extends from andis electrically connected to positive electrode bus 24 which poolscurrent from each member 22 of the population of positive electrodes.Positive electrode bus 24, in turn, may be used to electrically connecteach member 22 of the population of positive electrodes to the positiveterminal of an energy storage device (not shown) or to an externalenergy supply (not shown) or an external energy consumer (not shown).

Negative electrode bus 23 and positive electrode bus 24 may comprise anyof a wide range of electrically conductive materials. For example,negative electrode bus 23 and positive electrode bus 24 mayindependently comprise an electrically conductive ceramic, glass,polymer, semiconductor, or metal for electrically connecting the membersof the negative and positive electrode populations to the negative andpositive electrically conductive pathways 25, 26, respectively. By wayof further example, in one embodiment, negative electrode bus 23 andpositive electrode bus 24 each independently comprise an electricallyconductive material such as silicon, carbon, carbon composites, metalsilicides, and the like. Exemplary materials for the positive electrodebus include aluminum, carbon, chromium, gold, nickel, NiP, palladium,platinum, rhodium, ruthenium, an alloy of silicon and nickel, titanium,an alloy of one or more thereof, and combinations thereof. Exemplarymaterials for the negative electrode bus include copper, nickel,chromium, titanium, tungsten, cobalt, carbon, an alloy of one or morethereof, and combinations thereof. The materials for the positive andnegative electrode bus may be deposited by any of a range of well-known,metal deposition processes such as evaporation, sputtering, electrolessplating, immersion plating, electroplating and the like. In certainembodiments, the conductive portions of the positive and negativeelectrode buses may comprise the same material. In other embodiments,the conductive portions of the positive and negative electrode buses maycomprise compositionally different materials. In certain embodiments,the positive and/or negative electrode bus comprises a non-conductivecore partially or completely covered by a conductive material shell;additionally, in such embodiments in which the positive and negativeelectrode buses comprise a non-conductive core partially or completelycovered by a conductive material shell, the non-conductive cores of thepositive and negative electrode buses may have the same compositionwhile the conductive shells are compositionally different.

Electrically insulating separator layer 43 surrounds and electricallyisolates each member 21 of the negative electrode population from eachmember 22 of the positive electrode population and electrically isolatesnegative electrode bus 23 from positive electrode bus 24. Betweenadjacent negative electrode/positive electrode pairs (i.e., negativeelectrode/positive electrode pairs that provide the shortest distancefor a carrier ion to travel from a given member of the negativeelectrode population to a member of the positive electrode population orvice versa during a charging or discharging operation) electricallyinsulating separator layer 43 comprises a microporous separator materialthat can be permeated with a non-aqueous electrolyte as previouslydescribed; for example, as previously described in greater detail, inone embodiment the microporous separator material comprises pores havinga diameter of at least 50 Å, more typically in the range of about 2,500Å, and a porosity in the range of about 25% to about 75%, more typicallyin the range of about 35-55%.

In one embodiment, for example, and ignoring the porosity of themicroporous separator material, at least 70 vol % of electricallyinsulating separator material layer 43 between a member 21 of thenegative electrode population and the nearest member(s) 22 of thepositive electrode population (i.e., an “adjacent pair”) for ionexchange during a charging or discharging cycle is a microporousseparator material; stated differently, microporous separator materialconstitutes at least 70 vol. % of the electrically insulating materialbetween a negative electrode member 21 and a positive electrode member22. By way of further example, in one embodiment and ignoring theporosity of the microporous separator material, microporous separatormaterial constitutes at least 75 vol % of the electrically insulatingseparator material layer between adjacent pairs of members 21 andmembers 22 of the negative electrode population and positive electrodepopulation, respectively. By way of further example, in one embodimentand ignoring the porosity of the microporous separator material, themicroporous separator material constitutes at least 80 vol % of theelectrically insulating separator material layer between adjacent pairsof members 21 and members 22 of the negative electrode population andpositive electrode population, respectively. By way of further example,in one embodiment and ignoring the porosity of the microporous separatormaterial, the microporous separator material constitutes at least 85 vol% of the electrically insulating separator material layer betweenadjacent pairs of members 21 and members 22 of the negative electrodepopulation and positive electrode population, respectively. By way offurther example, in one embodiment and ignoring the porosity of themicroporous separator material, the microporous separator materialconstitutes at least 90 vol % of the electrically insulating separatormaterial layer between adjacent pairs of members 21 and members 22 ofthe negative electrode population and positive electrode population,respectively. By way of further example, in one embodiment and ignoringthe porosity of the microporous separator material, the microporousseparator material constitutes at least 95 vol % of the electricallyinsulating separator material layer between adjacent adjacent pairs ofmembers 21 and members 22 of the negative electrode population andpositive electrode population, respectively. By way of further example,in one embodiment and ignoring the porosity of the microporous separatormaterial, the microporous separator material constitutes at least 99 vol% of the electrically insulating separator material layer betweenadjacent pairs of members 21 and members 22 of the negative electrodepopulation and positive electrode population, respectively.

Referring now to FIG. 3, in one embodiment each member 21 of thepopulation of negative electrodes comprises negative electrode backbone51, negative electrode current collector layer 47, and negativeelectrode active material layer 49. Negative electrode active materiallayer 49 is bounded by lateral surfaces 61, 63, front surface 65 andback surface 67. Similarly, each member 22 of the population of positiveelectrodes comprises positive electrode backbone 52, positive electrodecurrent collector layer 48, and positive electrode active material layer50. Positive electrode active material layer 50 is bounded by lateralsurfaces 61, 63, front surface 65 and back surface 67. Each member 21 ofthe population of negative electrodes is separated from each member 22of the population of positive electrodes by electrically insulatingseparator layer 43 which surrounds longitudinal axis A_(NE) of eachmember 21 and longitudinal axis A_(PE) each member 22 of the populationsof negative and positive electrodes along at least a portion of theirrespective lengths.

Between opposing lateral surfaces 61, 62 and opposing lateral surfaces63, 64 of members 21, 22, respectively, electrically insulating materiallayer 43 comprises microporous separator material (as previouslydescribed). In one embodiment, for example, and ignoring the porosity ofthe microporous separator material, at least 70 vol % of electricallyinsulating separator material layer 43 between opposing lateral surfaces61, 62 and opposing lateral surfaces 63, 64 of members 21, 22,respectively, comprises microporous separator material (as previouslydescribed). By way of further example, in one embodiment and ignoringthe porosity of the microporous separator material, microporousseparator material constitutes at least 75 vol % of the electricallyinsulating separator material layer between opposing lateral surfaces61, 62 and opposing lateral surfaces 63, 64 of members 21, 22,respectively, comprises microporous separator material (as previouslydescribed). By way of further example, in one embodiment and ignoringthe porosity of the microporous separator material, the microporousseparator material constitutes at least 80 vol % of the electricallyinsulating separator material layer between opposing lateral surfaces61, 62 and opposing lateral surfaces 63, 64 of members 21, 22,respectively, comprises microporous separator material (as previouslydescribed). By way of further example, in one embodiment and ignoringthe porosity of the microporous separator material, the microporousseparator material constitutes at least 85 vol % of the electricallyinsulating separator material layer between opposing lateral surfaces61, 62 and opposing lateral surfaces 63, 64 of members 21, 22,respectively, comprises microporous separator material (as previouslydescribed). By way of further example, in one embodiment and ignoringthe porosity of the microporous separator material, the microporousseparator material constitutes at least 90 vol % of the electricallyinsulating separator material layer between opposing lateral surfaces61, 62 and opposing lateral surfaces 63, 64 of members 21, 22,respectively, comprises microporous separator material (as previouslydescribed). By way of further example, in one embodiment and ignoringthe porosity of the microporous separator material, the microporousseparator material constitutes at least 95 vol % of the electricallyinsulating separator material layer between opposing lateral surfaces61, 62 and opposing lateral surfaces 63, 64 of members 21, 22,respectively, comprises microporous separator material (as previouslydescribed). By way of further example, in one embodiment and ignoringthe porosity of the microporous separator material, the microporousseparator material constitutes at least 99 vol % of the electricallyinsulating separator material layer between opposing lateral surfaces61, 62 and opposing lateral surfaces 63, 64 of members 21, 22,respectively, comprises microporous separator material (as previouslydescribed).

During a discharge process, lithium ions (or other carrier ions such assodium, potassium, calcium or magnesium ions) leave the negativeelectrode active material layer 49 via lateral surfaces 61, 63 andtravel through the microporous separator material comprised byelectrically insulating separator layer 43 and into positive electrodeactive material layer 50 via lateral surfaces 62, 64. During a chargingprocess, lithium ions (or other carrier ions) leave positive electrodeactive material layer 50 through lateral surfaces 62, 64 and travelthrough the microporous separator material comprised by electricallyinsulating separator layer 43 and into negative electrode activematerial layer 49 via lateral surfaces 61, 63. Depending on the negativeelectrode active material used, the lithium ions (or other carrier ions)either intercalate (e.g., sit in a matrix of negative electrode activematerial without forming an alloy) or form an alloy. Coincident with themovement of lithium ions (or other carrier ions) between the positiveand negative electrodes, electrons are carried by negative electrodecurrent collector 47 and positive electrode current collector 48 to (orfrom) negative and positive electrode buses 23, 24, respectively (seeFIG. 2). Negative and positive electrode buses 23, 24, in turn, areelectrically connected to the negative and positive terminals of anenergy storage device (not shown) comprising electrode structure 20 orto an external energy supply (not shown) or an external energy consumer(not shown).

Negative electrode backbone 51 provides mechanical stability fornegative electrode active material layer 49. In general, negativeelectrode backbone 51 may comprise any material that may be shaped, suchas metals, semiconductors, organics, ceramics, and glasses. Presentlypreferred materials include semiconductor materials such as silicon andgermanium. Alternatively, however, carbon-based organic materials ormetals, such as aluminum, copper, nickel, cobalt, titanium, andtungsten, may also be incorporated into negative electrode backbones. Inone exemplary embodiment, negative electrode backbone 51 comprisessilicon. The silicon, for example, may be single crystal silicon,polycrystalline silicon, amorphous silicon or a combination thereof.

Depending upon the application, negative electrode backbone 51 may beelectrically conductive or insulating. For example, in one embodimentnegative electrode backbone 51 has an electrical conductivity of lessthan 10 Siemens/cm. By way of further example, in one embodimentnegative electrode backbone 51 has an electrical conductivity of lessthan 1 Siemens/cm. By way of further example, in one embodiment negativeelectrode backbone 51 has an electrical conductivity of less than 10⁻¹Siemens/cm. In other embodiments, negative electrode backbone 51 mayhave an electrical conductivity of at least 10 Siemens/cm. By way offurther example, in some embodiments negative electrode backbone 51 mayhave an electrical conductivity of at least 10² Siemens/cm. By way offurther example, in some embodiments negative electrode backbone 51 mayhave an electrical conductivity of at least 10³ Siemens/cm.

Negative electrode current collector layer 47 will typically have aconductivity of at least about 10³ Siemens/cm. For example, in one suchembodiment, negative electrode current collector layer 47 has aconductivity of at least about 10⁴ Siemens/cm. By way of furtherexample, in one such embodiment negative electrode current collectorlayer 47 has a conductivity of at least about 10⁵ Siemens/cm. Ingeneral, negative electrode current collector layer 47 may comprise anymetal or other conductor conventionally used as a current collectormaterial for negative electrodes such as carbon, cobalt, chromium,copper, nickel, titanium, or an alloy of one or more thereof. Negativeelectrode current collector 47 and may be fabricated by processes suchas electrodeposition, electroless deposition, immersion deposition,physical vapor deposition, chemical vapor deposition, and the like.

The thickness of negative electrode current collector layer 47 (i.e.,the shortest distance between the negative electrode backbone and thenegative electrode active material layer) in this embodiment will dependupon the composition of the layer and the performance specifications forthe electrochemical stack. In general, however, the thickness will rangefrom about 1 micrometer to about 100 micrometers.

Negative electrode active material layer 49 may comprise a negativeelectrode active material capable of absorbing and releasing a carrierion such as lithium, sodium, potassium, calcium or magnesium ions. Suchmaterials include carbon materials such as graphite and soft or hardcarbons, or any of a range of metals, semi-metals, alloys, oxides andcompounds capable of forming an alloy with lithium. Specific examples ofthe metals or semi-metals capable of constituting the anode materialinclude tin, lead, magnesium, aluminum, boron, gallium, silicon, indium,zirconium, germanium, bismuth, cadmium, antimony, silver, zinc, arsenic,hafnium, yttrium, and palladium. In one exemplary embodiment, negativeelectrode active material layer 49 comprises aluminum, tin, or silicon,or an oxide thereof, a nitride thereof, a fluoride thereof, or otheralloy thereof. In another exemplary embodiment, negative electrodeactive material layer 49 comprises silicon or an alloy thereof. In eachof the embodiments and examples recited in this paragraph, negativeelectrode active material layer 49 may be a particulate agglomerateelectrode or a monolithic electrode.

Positive electrode backbone 52 provides mechanical stability forpositive electrode active material layer 50. In general, positiveelectrode backbone 52 may comprise any material that may be shaped, suchas metals, semiconductors, organics, ceramics, and glasses. Presentlypreferred materials include semiconductor materials such as silicon andgermanium. Alternatively, however, carbon-based organic materials ormetals, such as aluminum, copper, nickel, cobalt, titanium, andtungsten, may also be incorporated into positive electrode backbones. Inone exemplary embodiment, positive electrode backbone 52 comprisessilicon. The silicon, for example, may be single crystal silicon,polycrystalline silicon, amorphous silicon or a combination thereof.

Depending upon the application, positive electrode backbone 52 may beelectrically conductive or insulating. For example, in one embodiment,positive electrode backbone 52 has an electrical conductivity of lessthan 10 Siemens/cm. By way of further example, in one embodimentpositive electrode backbone 52 has an electrical conductivity of lessthan 1 Siemens/cm. By way of further example, in one embodiment positiveelectrode backbone 52 has an electrical conductivity of less than 10⁻¹Siemens/cm. In other embodiments, positive electrode backbone 52 mayhave an electrical conductivity of at least 10 Siemens/cm. By way offurther example, in some embodiments positive electrode backbone 52 mayhave an electrical conductivity of at least 10² Siemens/cm. By way offurther example, in some embodiments positive electrode backbone 52 mayhave an electrical conductivity of at least 10³ Siemens/cm.

In the embodiment illustrated in FIG. 3, positive electrode currentcollector layer 48 is located between positive electrode backbone 52 andpositive electrode material layer 50 and will typically have aconductivity of at least about 10³ Siemens/cm. For example, in one suchembodiment, positive electrode current collector layer 48 has aconductivity of at least about 10⁴ Siemens/cm. By way of furtherexample, in one such embodiment positive electrode current collectorlayer 48 has a conductivity of at least about 10⁵ Siemens/cm. Positiveelectrode current collector 48 may comprise any of the metals previouslyidentified for the negative electrode current collector; for example, inone embodiment, positive electrode current collector 48 comprisesaluminum, carbon, chromium, gold, nickel, NiP, palladium, platinum,rhodium, ruthenium, an alloy of silicon and nickel, titanium, or acombination thereof (see “Current collectors for positive electrodes oflithium-based batteries” by A. H. Whitehead and M. Schreiber, Journal ofthe Electrochemical Society, 152(11) A2105-A2113 (2005)). By way offurther example, in one embodiment, positive electrode current collector48 comprises gold or an alloy thereof such as gold silicide. By way offurther example, in one embodiment, positive electrode current collector48 comprises nickel or an alloy thereof such as nickel silicide.Positive electrode current collector 48 may be fabricated by processessuch as electrodeposition, electroless deposition, immersion deposition,physical vapor deposition, chemical vapor deposition, and the like. Thepositive electrode and negative electrode current collectors may besimultaneously deposited, or sequentially fabricated using knownpatterning and metal deposition techniques.

Positive electrode active material layer 50 may comprise any of a rangeof cathode active materials, including mixtures of cathode activematerials. For example, for a lithium-ion battery, positive electrodeactive material layer 50 may comprise a cathode material selected fromtransition metal oxides, transition metal sulfides, transition metalnitrides, lithium-transition metal oxides, lithium-transition metalsulfides, and lithium-transition metal nitrides may be selectively used.The transition metal elements of these transition metal oxides,transition metal sulfides, and transition metal nitrides can includemetal elements having a d-shell or f-shell. Specific examples of suchmetal element are Sc, Y, lanthanoids, actinoids, Ti, Zr, Hf, V, Nb, Ta,Cr, Mo, W, Mn, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pb, Pt, Cu, Ag, andAu. Additional cathode active materials include LiCoO₂,LiNi_(0.5)Mn_(1.5)O₄, Li(Ni_(x)Co_(y)Al₂)O₂, LiFePO₄, Li₂MnO₄, V₂O₅,molybdenum oxysulfides, and combinations thereof. The positive electrodeactive material layer may be deposited to form the positive electrodestructure by any of a range of techniques including, for example,electrophoretic deposition, electrodeposition, co-deposition or slurrydeposition. In one exemplary embodiment, one of the aforementionedpositive electrode active materials, or a combination thereof, inparticulate form is electrophoretically deposited. In another exemplaryembodiment, a positive electrode active material such as V₂O₅ iselectrodeposited. In another exemplary embodiment, one of theaforementioned positive electrode active materials, or a combinationthereof, in particulate form is co-deposited in a conductive matrix suchas polyaniline. In another exemplary embodiment, one of theaforementioned positive electrode active materials, or a combinationthereof, in particulate form is slurry deposited.

Negative electrode backbone 51 and the positive electrode backbone 52may be fabricated in any method known in the art for fabricatingthree-dimensional structures. For example, a silicon backbone for thepositive electrode (cathode) and a silicon backbone for the negativeelectrode (anode) may be manufactured simultaneously by using a waferthat is bonded to a base by a temporary, permanent, or semi-permanentbond. Non-exhaustive methods of bonding a base to a wafer include,gluing using inorganic or organic gluing agents, anodic oxidationbonding, compression bonding, thermal bonding, and the like.Silicon-on-insulator wafers, anodic glass bonded wafers, temporarycarrier mounted wafers, are examples of a base bonded on to the activesubstrate. Subsequently, the wafer can be patterned and the silicon canbe removed in unwanted areas to leave behind structures that can act asthe backbone for the electrodes. In some embodiments, the backbones maybe manufactured in a negative fashion by removing materials from aplanar substrate in unwanted areas by laser machining, electricaldischarge machining, high precision machining, ablation, and drilling.In other embodiments, each backbone can individually or separately becreated in a positive fashion by building up layers using methods like3D printing, stencil printing and layering, gravure printing, injectionmolding, pressure molding and sintering, gel-casting and sintering,slurry-casting, tape-casting etc, with or without sintering,microforming, electroforming, etc. Other exemplary processes that may beused to make the backbones include growing pillars, rods, waves etc,using vacuum based deposition processes such as sputtering through amask, evaporation, etc. Still further exemplary methods formanufacturing include the use of nanowire or nanostructure growth on apatterned base material.

Negative electrode active material layer 49 may be formed or otherwiseassembled using methods such as electrodeposition, electrophoreticdeposition, vapor deposition, catalyst based growth such asVapor-Liquid-Solid deposition, gel-casting, tape casting, patterning andslurry deposition followed by densification by methods such assintering, binding etc. In some embodiments, the negative electrodematerial layer and the negative backbone may comprise the same material,such as silicon, aluminum, and tin, and the negative electrode materiallayer and the negative electrode backbone may be fabricatedsimultaneously. Similarly, positive electrode material layer 50 may beassembled using methods such as electrodeposition, electrophoreticdeposition, vapor deposition, catalyst based growth such asVapor-Liquid-Solid deposition, gel casting, tape casting, patterning andslurry deposition followed by densification by methods such as pressing,sintering, binding, curing, etc.

In one embodiment, negative electrode active material layer 49 ismicrostructured to provide a significant void volume fraction toaccommodate volume expansion and contraction as lithium ions (or othercarrier ions) are incorporated into or leave the negative electrodeactive material layer 49 during charging and discharging processes. Ingeneral, the void volume fraction of the negative electrode activematerial layer is at least 0.1. Typically, however, the void volumefraction of the negative electrode active material layer is not greaterthan 0.8. For example, in one embodiment, the void volume fraction ofthe negative electrode active material layer is about 0.15 to about0.75. By way of the further example, in one embodiment, the void volumefraction of the negative electrode active material layer is about 0.2 toabout 0.7. By way of the further example, in one embodiment, the voidvolume fraction of the negative electrode active material layer is about0.25 to about 0.6.

Depending upon the composition of the microstructured negative electrodeactive material layer and the method of its formation, themicrostructured negative electrode active material layer may comprisemacroporous, microporous or mesoporous material layers or a combinationthereof such as a combination of microporous and mesoporous or acombination of mesoporous and macroporous. Microporous material istypically characterized by a pore dimension of less than 10 nm, a walldimension of less than 10 nm, a pore depth of 1-50 micrometers, and apore morphology that is generally characterized by a “spongy” andirregular appearance, walls that are not smooth and branched pores.Mesoporous material is typically characterized by a pore dimension of10-50 nm, a wall dimension of 10-50 nm, a pore depth of 1-100micrometers, and a pore morphology that is generally characterized bybranched pores that are somewhat well defined or dendritic pores.Macroporous material is typically characterized by a pore dimension ofgreater than 50 nm, a wall dimension of greater than 50 nm, a pore depthof 1-500 micrometers, and a pore morphology that may be varied,straight, branched or dendritic, and smooth or rough-walled.Additionally, the void volume may comprise open or closed voids, or acombination thereof. In one embodiment, the void volume comprises openvoids, that is, the negative electrode active material layer containsvoids having openings at the lateral surface of the negative electrodeactive material layer (that is, the surface facing the separator and thepositive electrode active material layer) through which lithium ions (orother carrier ions) can enter or leave the negative electrode activematerial layer; for example, lithium ions may enter the negativeelectrode active material layer through the void openings after leavingthe positive electrode active material layer. In another embodiment, thevoid volume comprises closed voids, that is, the negative electrodeactive material layer contains voids that are enclosed by negativeelectrode active material. In general, open voids can provide greaterinterfacial surface area for the carrier ions whereas closed voids tendto be less susceptible to solid electrolyte interface (“SEI”) while eachprovides room for expansion of the negative electrode active materiallayer upon the entry of carrier ions. In certain embodiments, therefore,it is preferred that the negative electrode active material layercomprise a combination of open and closed voids.

In one embodiment, negative electrode active material layer 49 comprisesporous aluminum, tin or silicon or an alloy thereof. Porous siliconlayers may be formed, for example, by anodization, by etching (e.g., bydepositing precious metals such as gold, platinum, silver orgold/palladium on the (100) surface of single crystal silicon andetching the surface with a mixture of hydrofluoric acid and hydrogenperoxide), or by other methods known in the art such as patternedchemical etching. Additionally, the porous negative electrode activematerial layer will generally have a porosity fraction of at least about0.1 but less than 0.8 and have a thickness of about 1 to about 100micrometers. For example, in one embodiment negative electrode activematerial layer 49 comprises porous silicon, has a thickness of about 5to about 100 micrometers, and has a porosity fraction of about 0.15 toabout 0.75. By way of further example, in one embodiment, negativeelectrode active material layer 49 comprises porous silicon, has athickness of about 10 to about 80 micrometers, and has a porosityfraction of about 0.15 to about 0.7. By way of further example, in onesuch embodiment negative electrode active material layer 49 comprisesporous silicon, has a thickness of about 20 to about 50 micrometers, andhas a porosity fraction of about 0.25 to about 0.6. By way of furtherexample, in one embodiment negative electrode active material layer 49comprises a porous silicon alloy (such as nickel silicide), has athickness of about 5 to about 100 micrometers, and has a porosityfraction of about 0.15 to about 0.75.

In another embodiment, negative electrode active material layer 49comprises fibers of aluminum, tin or silicon, or an alloy thereof.Individual fibers may have a diameter (thickness dimension) of about 5nm to about 10,000 nm and a length generally corresponding to thethickness of the negative electrode active material layer 49. Fibers(nanowires) of silicon may be formed, for example, by chemical vapordeposition or other techniques known in the art such as vapor liquidsolid (VLS) growth and solid liquid solid (SLS) growth. Additionally,the negative electrode active material layer 49 will generally have aporosity fraction of at least about 0.1 but less than 0.8 and have athickness of about 1 to about 200 micrometers. For example, in oneembodiment negative electrode active material layer 49 comprises siliconnanowires, has a thickness of about 5 to about 100 micrometers, and hasa porosity fraction of about 0.15 to about 0.75. By way of furtherexample, in one embodiment, negative electrode active material layer 49comprises silicon nanowires, has a thickness of about 10 to about 80micrometers, and has a porosity fraction of about 0.15 to about 0.7. Byway of further example, in one such embodiment negative electrode activematerial layer 49 comprises silicon nanowires, has a thickness of about20 to about 50 micrometers, and has a porosity fraction of about 0.25 toabout 0.6. By way of further example, in one embodiment negativeelectrode active material layer 49 comprises nanowires of a siliconalloy (such as nickel silicide), has a thickness of about 5 to about 100micrometers, and has a porosity fraction of about 0.15 to about 0.75.

Although there may be significant fiber-to-fiber variation, nanowires ofaluminum, tin or silicon (or an alloy thereof) have major axes(sometimes referred to as a central axis) which are predominantlyperpendicular to the negative electrode backbone 51 (at the point ofattachment of the nanowire to the negative electrode active materiallayer).

In another embodiment, negative electrode active material layer 49comprises nanowires of silicon or an alloy thereof and porous silicon oran alloy thereof. In such embodiments, the negative electrode activematerial layer will generally have a porosity fraction of at least about0.1 but less than 0.8 and have a thickness of about 1 to about 100micrometers as previously described in connection with porous siliconand silicon nanowires.

Referring now to FIG. 4, each member 21 of the population of negativeelectrodes extends from inner surface 27 of negative electrode bus 23and each member 22 of the population of positive electrodes extends frominner surface 28 of positive electrode bus 24 with inner surfaces 27, 28facing or opposing each other. Negative electrode bus 23 comprises anelectrically conductive material electrically connecting each member 21of the negative electrode population to other members of the negativeelectrode population. Similarly, positive electrode bus 24 comprises anelectrically conductive material electrically connecting each member 22of the positive electrode population to each other. For ease ofillustration, electrically insulating separator material layer 43 (seeFIGS. 2 and 3) has been omitted.

Referring now to FIG. 5, each member 21 of the population of negativeelectrodes has bottom 31 proximate inner surface 27 of negativeelectrode bus 23, top 33 distal to inner surface 27, width W_(NE),length L_(NE) and longitudinal axis A_(NE). Length L_(NE) corresponds tothe distance between bottom 31 and top 33 and is measured in a directionfrom inner surface 27 along longitudinal axis A_(NE) that issubstantially perpendicular to direction D. In the context of the X-Y-Zcoordinate system depicted in FIG. 2, length L_(NE) is measured alongthe “X” axis (and perpendicular to direction D).

Referring now to FIG. 7, each member 21 of the population of negativeelectrodes has width W_(NE), height H_(NE) and perimeter P_(NE) whereinwidth W_(NE) and height H_(NE) are measured in directions that areperpendicular to each other and to the direction in which length L_(NE)is measured. In this embodiment, perimeter P_(NE) has a value that isequal to 2W_(NE)+2H_(NE). Width W_(NE) and height H_(NE) will varydepending upon the energy storage device and its intended use, but inmany embodiments the value of W_(NE) will be within the range of about0.01 mm to 2.5 mm and the value of H_(NE) will be within the range ofabout 0.05 mm to 10 mm. For example, in one embodiment W_(NE) will be inthe range of about 0.025 mm to about 2 mm. By way of further example, inone embodiment W_(NE) will be in the range of about 0.05 mm to about 1mm. By way of further example, in one embodiment H_(NE) will be in therange of about 0.05 mm to about 5 mm. By way of further example, in oneembodiment H_(NE) will be in the range of about 0.05 mm to about 1 mm.In general, L_(NE) (see FIG. 5) will be substantially greater than eachof W_(NE) and H_(NE); for example, in one embodiment, the ratio ofL_(NE) to each of W_(NE) and H_(NE) is at least 5:1, respectively (thatis, the ratio of L_(NE) to W_(NE) is at least 5:1, respectively and theratio of L_(NE) to H_(NE) is at least 5:1, respectively). By way offurther example, in one embodiment the ratio of L_(NE) to each of W_(NE)and H_(NE) is at least 10:1. By way of further example, in oneembodiment, the ratio of L_(NE) to each of W_(NE) and H_(NE) is at least15:1. By way of further example, in one embodiment, the ratio of L_(NE)to each of W_(NE) and H_(NE) is at least 20:1. Additionally, it isgenerally preferred that L_(NE) be substantially greater than theperimeter P_(NE); for example, in one embodiment, the ratio of L_(NE) toP_(NE) is at least 1.25:1, respectively. By way of further example, inone embodiment the ratio of L_(NE) to P_(NE) is at least 2.5:1,respectively. By way of further example, in one embodiment, the ratio ofL_(NE) to P_(NE) is at least 3.75:1, respectively. Additionally, theratio of H_(NE) to W_(NE) will generally be at least 0.4:1,respectively. For example, in one embodiment, the ratio of H_(NE) toW_(NE) will be at least 2:1, respectively. By way of further example, inone embodiment the ratio of H_(NE) to W_(NE) will be at least 10:1,respectively. By way of further example, in one embodiment the ratio ofH_(NE) to W_(NE) will be at least 20:1, respectively. Typically,however, the ratio of H_(NE) to W_(NE) will generally be less than1,000:1, respectively. For example, in one embodiment the ratio ofH_(NE) to W_(NE) will be less than 500:1, respectively. By way offurther example, in one embodiment the ratio of H_(NE) to W_(NE) will beless than 100:1, respectively. By way of further example, in oneembodiment the ratio of H_(NE) to W_(NE) will be less than 10:1,respectively. By way of further example, in one embodiment the ratio ofH_(NE) to W_(NE) will be in the range of about 2:1 to about 100:1,respectively. In the context of the X-Y-Z coordinate system depicted inFIG. 2, length L_(NE) is measured along the “X” axis (and perpendicularto direction D), W_(NE) is measured along the “Y” axis, and H_(NE) ismeasured along the “Z” axis.

Typically, negative electrode backbone 51 will have a thickness of atleast 1 micrometer when measured in the same direction as width W_(NE)of the negative electrode (see FIG. 7). Negative electrode backbone 51may be substantially thicker, but typically will not have a thickness inexcess of 100 micrometers; greater thickness are feasible but maynegatively impact energy density. For example, in one embodiment,negative electrode backbone 51 will have a thickness of about 1 to about50 micrometers. In general, negative electrode backbone 51 will haveheight H_(NB) (when measured in the same direction as height H_(NE) ofthe negative electrode) of at least about 50 micrometers, more typicallyat least about 100 micrometers. In general, however, negative electrodebackbone 51 will typically have a height of no more than about 10,000micrometers, and more typically no more than about 5,000 micrometers. Byway of example, in one embodiment, negative electrode backbone 51 willhave a thickness of about 5 to about 50 micrometers and a height ofabout 50 to about 5,000 micrometers. By way of further example, in oneembodiment, negative electrode backbone 51 will have a thickness ofabout 5 to about 20 micrometers and a height of about 100 to about 1,000micrometers. By way of further example, in one embodiment, negativeelectrode backbone 51 will have a thickness of about 5 to about 20micrometers and a height of about 100 to about 2,000 micrometers.

Negative electrode active material layer 49 will have a thickness (e.g.,the shortest distance between current collector layer 47 andelectrically insulating separator layer 43 as illustrated in FIG. 3 andwhen measured in the same direction as width W_(NE) of the negativeelectrode) of at least 1 micrometer. In general, however, negativeelectrode active material layer 49 will typically have a thickness thatdoes not exceed 200 micrometers. For example, in one embodiment,negative electrode active material layer 49 will have a thickness ofabout 1 to about 100 micrometers. By way of further example, in oneembodiment, negative electrode active material layer 49 will have athickness of about 2 to about 75 micrometers. By way of further example,in one embodiment, negative electrode active material layer 49 will havea thickness of about 10 to about 100 micrometers. By way of furtherexample, in one embodiment, negative electrode active material layer 49will have a thickness of about 5 to about 50 micrometers. Additionally,the layer of negative electrode active material 49 on each of thelateral surfaces of negative electrode backbone 51 will have a height(when measured in a direction corresponding to the height H_(NE) of thenegative electrode as illustrated in FIG. 5) of at least about 50micrometers, more typically at least about 100 micrometers. In general,however, negative electrode active material layer 49 will typically havea height of no more than about 10,000 micrometers, and more typically nomore than about 7,500 micrometers. By way of example, in one embodiment,negative electrode active material layer 49 will have a thickness ofabout 1 to about 200 micrometers and a height of about 50 to about 7,500micrometers. By way of further example, in one embodiment, negativeelectrode active material layer 49 will have a thickness of about 1 toabout 50 micrometers and a height of about 100 to about 1,000micrometers. By way of further example, in one embodiment, negativeelectrode active material layer 49 will have a thickness of about 5 toabout 20 micrometers and a height of about 100 to about 1,000micrometers. By way of further example, in one embodiment, negativeelectrode active material layer 49 will have a thickness of about 10 toabout 100 micrometers and a height of about 100 to about 1,000micrometers. By way of further example, in one embodiment, negativeelectrode active material layer 49 will have a thickness of about 5 toabout 50 micrometers and a height of about 100 to about 1,000micrometers.

Referring now to FIG. 6, each member 22 of the population of positiveelectrodes has bottom 32 proximate inner surface 28 of positiveelectrode bus 24, top 34 distal to positive electrode substrate surface26, width W_(PE), length L_(PE) and longitudinal axis A_(PE). LengthL_(PE) corresponds to the distance between bottom 32 and top 34 and ismeasured in a direction along longitudinal axis A_(PE) from innersurface 28 that is substantially perpendicular to direction D. In thecontext of the X-Y-Z coordinate system depicted in FIG. 2, length L_(PE)is measured along the “X” axis (and perpendicular to direction D).

Referring now to FIG. 8, each member 22 of the population of positiveelectrodes has width W_(PE), height H_(PE) and perimeter P_(PE) whereinwidth W_(PE) and height H_(PE) are measured in directions that areperpendicular to each other and to the direction in which length L_(PE)is measured. In this embodiment, perimeter P_(PE) has a value that isequal to 2W_(PE)+2H_(PE). Width W_(PE) and height H_(PE) will varydepending upon the energy storage device and its intended use, but inmany embodiments W_(PE) will be within the range of about 0.01 mm to 2.5mm and the value of H_(PE) will be within the range of about 0.05 mm to10 mm. For example, in one embodiment W_(PE) will be in the range ofabout 0.025 mm to about 2 mm. By way of further example, in oneembodiment W_(PE) will be in the range of about 0.05 mm to about 1 mm.By way of further example, in one embodiment H_(PE) will be in the rangeof about 0.05 mm to about 5 mm. By way of further example, in oneembodiment H_(PE) will be in the range of about 0.05 mm to about 1 mm.In general, L_(PE) (see FIG. 6) will be substantially greater than eachof W_(PE) and H_(PE); for example, in one embodiment, the ratio ofL_(PE) to each of W_(PE) and H_(PE) is at least 5:1, respectively (thatis, the ratio of L_(PE) to W_(PE) is at least 5:1, respectively and theratio of L_(PE) to H_(PE) is at least 5:1, respectively). By way offurther example, in one embodiment the ratio of L_(PE) to each of W_(PE)and H_(PE) is at least 10:1. By way of further example, in oneembodiment, the ratio of L_(PE) to each of W_(PE) and H_(PE) is at least15:1. By way of further example, in one embodiment, the ratio of L_(PE)to each of W_(PE) and H_(PE) is at least 20:1. Additionally, it isgenerally preferred that L_(PE) be substantially greater than theperimeter P_(PE); for example, in one embodiment, the ratio of L_(PE) toP_(PE) is at least 1.25:1, respectively. By way of further example, inone embodiment the ratio of L_(PE) to P_(PE) is at least 2.5:1,respectively. By way of further example, in one embodiment, the ratio ofL_(PE) to P_(PE) is at least 3.75:1, respectively. Additionally, theratio of H_(PE) to W_(PE) will generally be at least 0.4:1,respectively. For example, in one embodiment, the ratio of H_(PE) toW_(PE) will be at least 2:1, respectively. By way of further example, inone embodiment the ratio of H_(PE) to W_(PE) will be at least 10:1,respectively. By way of further example, in one embodiment the ratio ofH_(PE) to W_(PE) will be at least 20:1, respectively. Typically,however, the ratio of H_(PE) to W_(PE) will generally be less than1,000:1, respectively. For example, in one embodiment the ratio ofH_(PE) to W_(PE) will be less than 500:1, respectively. By way offurther example, in one embodiment the ratio of H_(PE) to W_(PE) will beless than 100:1, respectively. By way of further example, in oneembodiment the ratio of H_(PE) to W_(PE) will be less than 10:1,respectively. By way of further example, in one embodiment the ratio ofH_(PE) to W_(PE) will be in the range of about 2:1 to about 100:1,respectively. In the context of the X-Y-Z coordinate system depicted inFIG. 2, in a preferred embodiment length L_(PE) is measured along the“X” axis (and perpendicular to direction D), W_(PE) is measured alongthe “Y” axis, and H_(PE) is measured along the “Z” axis.

Typically, positive electrode backbone 52 will have a thickness of atleast 1 micrometer when measured in the same direction as width W_(PE)of the positive electrode (see FIG. 8). Positive electrode backbone 52may be substantially thicker, but generally will not have a thickness inexcess of 100 micrometers. For example, in one embodiment, positivebackbone 52 will have a thickness of about 1 to about 50 micrometers. Ingeneral, positive electrode backbone 52 will have a height H_(PE) (whenmeasured in the same direction as height H_(NE) of the negativeelectrode) of at least about 50 micrometers, more typically at leastabout 100 micrometers. In general, however, positive electrode backbone52 will typically have a height of no more than about 10,000micrometers, and more typically no more than about 5,000 micrometers. Byway of example, in one embodiment, positive electrode backbone 52 willhave a thickness of about 5 to about 50 micrometers and a height ofabout 50 to about 5,000 micrometers. By way of further example, in oneembodiment, positive electrode backbone 52 will have a thickness ofabout 5 to about 20 micrometers and a height of about 100 to about 1,000micrometers. By way of further example, in one embodiment, positiveelectrode backbone 52 will have a thickness of about 5 to about 20micrometers and a height of about 100 to about 2,000 micrometers.

Positive electrode active material layer 50 will have a thickness (e.g.,the shortest distance between current collector layer 48 andelectrically insulating separator layer 43 as illustrated in FIG. 3 andwhen measured in the same direction as width W_(PE) of the positiveelectrode) of at least 1 micrometer. In general, however, positiveelectrode active material layer 50 will typically have a thickness thatdoes not exceed 500 micrometers. For example, in one embodiment,positive electrode active material layer 50 will have a thickness ofabout 1 to about 200 micrometers. By way of further example, in oneembodiment, positive electrode active material layer 50 will have athickness of about 2 to about 100 micrometers. By way of furtherexample, in one embodiment, positive electrode active material layer 50will have a thickness of about 10 to about 100 micrometers. By way offurther example, in one embodiment, positive electrode active materiallayer 50 will have a thickness of about 5 to about 50 micrometers.Additionally, the layer of positive electrode active material 50 on eachof the lateral surfaces of positive electrode backbone 51 will have aheight (when measured in a direction corresponding to the height H_(PE)of the positive electrode as illustrated in FIG. 6) of at least about 50micrometers, more typically at least about 100 micrometers. In general,however, positive electrode active material layer 50 will typically havea height of no more than about 10,000 micrometers, and more typically nomore than about 7,500 micrometers. By way of example, in one embodiment,positive electrode active material layer 50 will have a thickness ofabout 1 to about 200 micrometers and a height of about 50 to about 7,500micrometers. By way of further example, in one embodiment, positiveelectrode active material layer 50 will have a thickness of about 1 toabout 50 micrometers and a height of about 100 to about 1,000micrometers. By way of further example, in one embodiment, positiveelectrode active material layer 50 will have a thickness of about 5 toabout 20 micrometers and a height of about 100 to about 1,000micrometers. By way of further example, in one embodiment, positiveelectrode active material layer 50 will have a thickness of about 10 toabout 100 micrometers and a height of about 100 to about 1,000micrometers. By way of further example, in one embodiment, positiveelectrode active material layer 50 will have a thickness of about 5 toabout 50 micrometers and a height of about 100 to about 1,000micrometers.

Referring now to FIG. 9, in one embodiment, electrically insulatingseparator layer 43 extends from surface 28 of positive electrode bus 24to surface 27 of negative electrode bus 23 and surrounds axes A_(PE) andA_(NE) of members 22 and member 21, respectively, for the entirety oflengths L_(PE) and L_(NE) of members 22 and 21, respectively. In onesuch embodiment, electrically insulating separator layer 43 comprisesmicroporous separator material (as previously described) and themicroporous separator material surrounds axes A_(PE) and A_(NE) ofmembers 22 and member 21, respectively, for the entirety of lengthsL_(PE) and L_(NE) of members 22 and 21, respectively. Electricallyinsulating material layer 43 also comprises microporous separatormaterial (as previously described) in the region between top 33 ofnegative electrode 21 and surface 28 of positive electrode bus 24. Inthis embodiment, therefore, electrically insulating material layer 43surrounds each member 21 of the population of negative electrodes andeach member 22 of the population of positive electrodes; stateddifferently, in this embodiment, electrically insulating material layer43 (i) surrounds longitudinal axis A_(NE) of each member 21 for the fulllength L_(NE) of each member 21 of the population of negative electrodesand top 33 of each member 21 of the population of negative electrodesand (ii) surrounds longitudinal axis A_(PE) of each member 22 for thefull length L_(PE) of each member 22 of the population of positiveelectrodes and top 34 of each member 22 of the population of positiveelectrodes.

Referring now to FIG. 10, in one embodiment three-dimensional battery 70of the present invention comprises battery enclosure 72, electrode stack74, negative electrode tab 41 and positive electrode tab 42 forelectrically connecting electrode stack 74 to an external energy supplyor consumer (not shown). Electrode stack 74 comprises six electrodestructures 20 (see FIG. 2) stacked in a direction that is perpendicularto the direction of the progression of the series of interdigitatedelectrodes within each electrode structure 20; referring again to FIG.2, the direction of stacking of the six electrode structures in thisembodiment is in the “Z” direction relative to the X-Y-Z coordinatesystem illustrated in FIG. 2 and perpendicular to direction D. Thenumber of electrode structures in an electrode stack 74 is not criticaland may range, for example, from 1 to 50, with 2 to 20 electrodestructures in an electrode stack being typical. After filling thebattery enclosure with a non-aqueous electrolyte, battery enclosure 72may be sealed by folding lid 72A at hinge 72B and gluing lid 72A toupper surface 72C.

In one embodiment, negative electrode tab extension 25 is electricallyconnected to the negative electrode bus 23 of each electrode structure20 in stack 74 (using, for example, an electrically conductive glue) andpositive electrode tab extension 26 is electrically connected to thepositive electrode bus 24 of each electrode structure 20 in stack 74(using, for example, an electrically conductive glue). As illustrated,negative electrode tab extension 25 is electrically connected to thenegative electrode bus 23 and positive electrode tab extension 26 iselectrically connected to the positive electrode bus 24 of each of sixelectrode structures 20; in other embodiments, negative and positiveelectrode tab extensions 25, 26 may be electrically connected to agreater or lesser number of negative and positive electrode buses withinan electrode stack 74 and may range, for example, from 1 to 50, with 2to 20 being typical. In one alternative embodiment, and independent ofthe number of electrode structures in a stack, stack 74 may comprise twoor more negative electrode tab extensions 25 and two or more positiveelectrode tab extensions 26.

Negative electrode tab 41 and negative electrode tab extension 25 andpositive electrode tab 42 and positive electrode tab extension 42 maycomprise any of a wide range of electrically conductive materials. Forexample, in one embodiment, negative electrode tab 41, negativeelectrode tab extension 25, positive electrode tab 42 and positiveelectrode tab extension 42 independently comprise an electricallyconductive material such as silicon, carbon, carbon composites, metalsilicides, and the like. Exemplary materials for the positive electrodetab and positive electrode tab extension include the same materials asthose identified for the positive electrode bus and exemplary materialsfor the negative electrode tab and negative electrode tab extensioninclude the same materials as those identified for the negativeelectrode bus.

Negative electrode tab 41, negative electrode tab extension 25, positiveelectrode tab 42 and positive electrode tab extension 26 may be attachedto negative electrode bus 23 and positive electrode bus 24,respectively, by a range of techniques. Methods for attachment of thetabs, tab extensions, and the buses may include gluing, soldering,bonding, sintering, press contacting, brazing, thermal spraying joining,clamping or combinations thereof. Gluing may include joining thematerials with conductive materials such as conducting epoxies,conducting elastomers, mixtures of insulating organic glue filled withconducting metals, such as nickel filled epoxy, carbon filled epoxy etc.Conductive pastes may be used to join the materials together and thejoining strength could be tailored by temperature (sintering), light (UVcuring, cross-linking), chemical curing (catalyst based cross linking).Bonding processes may include wire bonding, ribbon bonding, ultrasonicbonding. Welding processes may include ultrasonic welding, resistancewelding, laser beam welding, electron beam welding, induction welding,and cold welding. Joining of these materials can also be performed byusing a coating process such as a thermal spray coating such as plasmaspraying, flame spraying, arc spraying, to join materials together. Byway of example, a nickel or copper mesh can be joined onto a nickel bususing a thermal spray of nickel as a glue.

Referring now to FIG. 11, battery enclosure 72 is filled withnon-aqueous electrolyte (not shown) and lid 72A may be folded over andsealed to upper surface (see FIG. 10)) to enclose electrode stack 74. Topermit connection to an energy supply or consumer (not shown), tabs 41,42 extend out of the sealed enclosure in a direction that isperpendicular to the direction of stacking of the individual electrodestructures 20 in electrode stack 74 and parallel to the direction of theprogression of the series of interdigitated electrodes in each electrodestructure 20 in electrode stack 74.

In certain embodiments, a battery enclosure may contain two or moreelectrode structures (sometimes also referred to as dies) stackedvertically, horizontally or vertically and horizontally, relative toeach other, and the tab extensions are connected to each of theelectrode in order to provide electrical connection to the environmentoutside the battery. When dies are stacked vertically, the bottoms ofthe populations of negative electrodes in different electrode structures(or the negative electrode buses, whichever is present) are verticallypositioned relative to each other and the bottoms of the populations ofpositive electrodes in different electrode structures (or the positiveelectrode buses, whichever is present) are vertically positionedrelative to each other. In certain embodiments, each electrode structurein a stack has a top and bottom coating of separator material asillustrated in FIG. 2. In other embodiments, however, the top, bottom ortop and bottom coating of separator material may be omitted, and afree-standing separator layer may be inserted between the electrodestructures (dies) to provide electrical isolation. Commerciallyavailable battery separators may be cut to the desired size and used forthis purpose. Once the dies are stacked, in some embodiments, the tabextension(s) for the positive and negative electrode populations in theelectrode structures are electrically connected to the ends of theelectrode buses (if present) or the electrode ends of the respectivepopulations by gluing, plasma spraying, welding, etc. Depending upon theintended application, each tab extension may be connected to anindividual electrode structure (die) in the electrode stack.Alternatively, a single tab extension may be electrically connected totwo or more electrode structures (die) in the stack; in one suchembodiment, the tab extension spans the height of the stack (see, e.g.,26 in FIG. 10) and makes electrical connection to all electrodestructures (die) in the stack.

Instead of stacking dies vertically one on top of another, in oneembodiment dies are tiled next to each other in the X plane. The tilingcan occur along only one axis (for example X only) or along both axis.In one such embodiment the polarity of the electrode buses on each dieare alternately reversed so that the cathode bus from one die isadjacent the cathode bus from the next die and the anode bus of one dieis next to the anode bus of the next die. In this manner, a common tabcan be used to connect to two adjacent die saving weight and volume.When tiling in the XY plane, multiple anode and/or cathode tabs may needto be connected together to form a single anode connection and a singlecathode connection. This can be achieved inside the battery enclosure oroutside the battery enclosure. In certain embodiments multiple anodetabs and/or multiple cathode tabs may remain unconnected and come out ofthe battery enclosure. Alternatively, a single anode and cathodeconnection may be brought outside the battery enclosure. In thisembodiment, the cathode tabs are initially shaped in a T configuration.The top of the T connects to two adjacent cathode buses. The bottom ofthe T is bent at 90 degrees and runs along the bottom of the tiled dies.The bottom portion of multiple cathode tabs lay on top of each otheralong the bottom of the tiled dies. These multiple tabs can then beelectrically connected together by resistance welding, laser welding,spot welding or connected with conductive glue. Only one of thesecathode tabs is then brought outside the battery enclosure. Similarly,multiple anode tabs are initially shaped in a T configuration. The topof the T connects to two adjacent anode buses. The bottom of the T isbent at 90 degrees and runs along the bottom of the tiled dies. Thebottom portion of multiple anode tabs lay on top of each other along thebottom of the tiled dies. These multiple tabs can then be electricallyconnected together by resistance welding, laser welding, spot welding orconnected with conductive glue. Only one of these anode tabs is thenbrought outside the battery enclosure. Tiling in the XY plane can alsobe combined with stacking die in the Z plane. In this manner, batteriescan be manufactured that are much larger than each individual die.

For lithium ion batteries for portable electronics such as mobile phonesand computers, for example, a pouch or other conventional batteryenclosure may be substituted for battery enclosure 72.

Referring now to FIG. 12, in one alternative embodiment, electricallyinsulating separator layer 43 surrounds axis A_(NE) of each member 21 ofthe population of negative electrodes; in this embodiment electricallyinsulating separator layer 43 is between adjacent pairs of negativeelectrode members 21 and positive electrode members 22 but does notsurround axis A_(PE) of each member 22 of the population of positiveelectrodes. Between opposing lateral surfaces 61, 62 of members 21, 22,respectively and between opposing lateral surfaces 63, 64 of members 21,22, respectively, electrically insulating separator layer 43 comprisesmicroporous separator material (as previously described). For example,in one such embodiment, electrically insulating separator layer 43comprises microporous separator material (as previously described) andthe microporous separator material surrounds axis A_(NE) of each member21 for at least 70% of length L_(NE) of each member 21. By way offurther example, in one such embodiment electrically insulatingseparator layer 43 comprises microporous separator material (aspreviously described) and the microporous separator material surroundsaxis A_(NE) of each member 21 for at least 75% of length L_(NE) of eachmember 21. By way of further example, in one such embodimentelectrically insulating separator layer 43 comprises microporousseparator material (as previously described) and the microporousseparator material surrounds axis A_(NE) of each member 21 for at least80% of length L_(NE) of each member 21. By way of further example, inone such embodiment electrically insulating separator layer 43 comprisesmicroporous separator material (as previously described) and themicroporous separator material surrounds axis A_(NE) of each member 21for at least 85% of length L_(NE) of each member 21. By way of furtherexample, in one such embodiment electrically insulating separator layer43 comprises microporous separator material (as previously described)and the microporous separator material surrounds axis A_(NE) of eachmember 21 for at least 90% of length L_(NE) of each member 21. By way offurther example, in one such embodiment electrically insulatingseparator layer 43 comprises microporous separator material (aspreviously described) and the microporous separator material surroundsaxis A_(NE) of each member 21 for at least 95% of length L_(NE) of eachmember 21. By way of further example, in one such embodimentelectrically insulating separator layer 43 comprises microporousseparator material (as previously described) and the microporousseparator material surrounds axis A_(NE) of each member 21 for theentirety of length L_(NE) of each member 21. In each of the foregoingexemplary embodiments, electrically insulating separator layer 43 alsocomprises microporous separator material (as previously described) inthe region surrounding front surface 65 and back surface 67 of members21.

Referring now to FIG. 13, in an alternative embodiment height H_(NE) ofeach member 21 of the population of negative electrodes may be less thanheight H_(PE) of each member 22 of the population of positiveelectrodes. In this embodiment, and as more fully described inconnection with FIG. 12, electrically insulating separator layer 43surrounds axis A_(NE) of each member 21 of the population of negativeelectrodes for at least a majority (e.g., at least 70%, at least 75%, atleast 80%, at least 85%, at least 90%, at least 95%, or even theentirety) of length L_(NE) of each member 21 of the negative electrodepopulation. Electrically insulating separator layer 43 also comprisesmicroporous separator material (as previously described) in the regionsurrounding front surface 65 and back surface 67 of members 21.

Referring now to FIG. 14, in one alternative embodiment, electricallyinsulating separator layer 43 surrounds axis A_(PE) of each member 22 ofthe population of positive electrodes; in this embodiment electricallyinsulating separator layer 43 is between adjacent pairs of negativeelectrode members 21 and positive electrode members 22 but does notsurround axis A_(NE) of each member 21 of the population of negativeelectrodes. Between opposing lateral surfaces 61, 62 of members 21, 22,respectively, and between opposing lateral surfaces 63, 64 of members21, 22, respectively, electrically insulating separator layer 43comprises microporous separator material (as previously described). Forexample, in one such embodiment, electrically insulating separator layer43 comprises microporous separator material (as previously described)and the microporous separator material surrounds axis A_(PE) of eachmember 22 for at least 70% of length L_(PE) of each member 22. By way offurther example, in one such embodiment electrically insulatingseparator layer 43 comprises microporous separator material (aspreviously described) and the microporous separator material surroundsaxis A_(PE) of each member 22 for at least 75% of length L_(PE) of eachmember 22. By way of further example, in one such embodimentelectrically insulating separator layer 43 comprises microporousseparator material (as previously described) and the microporousseparator material surrounds axis A_(PE) of each member 22 for at least80% of length L_(PE) of each member 22. By way of further example, inone such embodiment electrically insulating separator layer 43 comprisesmicroporous separator material (as previously described) and themicroporous separator material surrounds axis A_(PE) of each member 22for at least 85% of length L_(PE) of each member 22. By way of furtherexample, in one such embodiment electrically insulating separator layer43 comprises microporous separator material (as previously described)and the microporous separator material surrounds axis A_(PE) of eachmember 22 for at least 90% of length L_(PE) of each member 22. By way offurther example, in one such embodiment electrically insulatingseparator layer 43 comprises microporous separator material (aspreviously described) and the microporous separator material surroundsaxis A_(PE) of each member 22 for at least 95% of length L_(PE) of eachmember 22. By way of further example, in one such embodimentelectrically insulating separator layer 43 comprises microporousseparator material (as previously described) and the microporousseparator material surrounds axis A_(PE) of each member 22 for theentirety of length L_(PE) of each member 22. In each of the foregoingexemplary embodiments, electrically insulating separator layer 43 alsocomprises microporous separator material (as previously described) inthe region surrounding front surface 66 and back surface 68 of members22.

In an alternative embodiment, electrically insulating separator layer 43surrounds axis A_(PE) of each member 22 of the population of positiveelectrodes as described in connection with FIG. 14, but height H_(NE) ofeach member 21 of the population of negative electrodes is greater thanheight H_(PE) of each member 22 of the population of positiveelectrodes. In this alternative embodiment electrically insulatingseparator layer 43 surrounds axis A_(PE) of each member 22 of thepopulation of positive electrodes for at least a majority (e.g., atleast 70%, at least 75%, at least 80%, at least 85%, at least 90%, atleast 95%, or even the entirety) of length L_(PE) of each member 22 ofthe positive electrode population. Electrically insulating separatorlayer 43 also comprises microporous separator material (as previouslydescribed) in the region surrounding front surface 66 and back surface68 of members 22.

Referring now to FIG. 15, in one embodiment electrically insulatingseparator layers 43, 86, and 88, in combination, surround (i) axisA_(NE) of each member 21 of the population of negative electrodes and(ii) axis A_(PE) of each member 22 of the population of positiveelectrodes. Electrically insulating separator layer 43 comprisesmicroporous separator material (as previously described) in the regionbetween opposing lateral surfaces 61, 62 of members 21, 22, respectivelyand between opposing lateral surfaces 63, 64 of members 21, 22,respectively. Because the primary route for ion transfer between members21 and members 22 occurs between the lateral surfaces of these members,electrically insulating separator layers 86, 88 may comprise anyelectrically insulating material suitable for use in a secondarybattery; in one such embodiment, electrically insulating separatorlayers 86, 88 comprise an electrically insulating material that has lowelectronic and ionic conductivity for carrier ions (e.g., lithium ions).For example, in one embodiment the electrically insulating material hasa conductivity for carrier ions (e.g., lithium) of less than 1×10⁻⁴S/cm. By way of further example in one embodiment the particulatematerial has a conductivity for carrier ions of less than 1×10⁻⁵ S/cm.By way of further example in one embodiment the particulate material hasa conductivity for carrier ions of less than 1×10⁻⁶ S/cm. Exemplaryparticulate materials include any of the materials previously identifiedas exemplary particulate material for the microporous separatormaterial. In one exemplary embodiment, electrically insulating separatorlayers 43, 86, and 88, in combination surround axis A_(NE) of eachmember 21 for at least 70% of length L_(NE) of each member 21 andsurround axis A_(PE) of each member 22 for at least 70% of length L_(PE)of each member 22. By way of further example, in one such embodimentelectrically insulating separator layers 43, 86, and 88, in combinationsurround axis A_(NE) of each member 21 for at least 75% of length L_(NE)of each member 21 and surround axis A_(PE) of each member 22 for atleast 75% of length L_(PE) of each member 22. By way of further example,in one such embodiment electrically insulating separator layers 43, 86,and 88, in combination, surround axis A_(NE) of each member 21 for atleast 80% of length L_(NE) of each member 21 and surround axis A_(PE) ofeach member 22 for at least 80% of length L_(PE) of each member 22. Byway of further example, in one such embodiment electrically insulatingseparator layers 43, 86, and 88, in combination, surround axis A_(NE) ofeach member 21 for at least 85% of length L_(NE) of each member 21 andsurround axis A_(PE) of each member 22 for at least 85% of length L_(PE)of each member 22. By way of further example, in one such embodimentelectrically insulating separator layers 43, 86, and 88, in combination,surround axis A_(NE) of each member 21 for at least 90% of length L_(NE)of each member 21 and surround axis A_(PE) of each member 22 for atleast 90% of length L_(PE) of each member 22. By way of further example,in one such embodiment electrically insulating separator layers 43, 86,and 88, in combination, surround axis A_(NE) of each member 21 for atleast 95% of length L_(NE) of each member 21 and surround axis A_(PE) ofeach member 22 for at least 95% of length L_(PE) of each member 22. Byway of further example, in one such embodiment electrically insulatingseparator layers 43, 86, and 88, in combination, surround axis A_(NE) ofeach member 21 for the entirety of length L_(NE) of each member 21 andsurround axis A_(PE) of each member 22 for the entirety of length L_(PE)of each member 22.

Referring now to FIG. 16, in one alternative embodiment electricallyinsulating separator layers 43, 86, and 88, in combination, surroundaxis A_(NE) of each member 21 of the population of negative electrodes.In this embodiment electrically insulating separator layer 43 is betweenmembers 22 of the population of positive electrodes and members 21 ofthe population of negative electrodes and electrically insulatingseparator layers 86 and 88 are elsewhere. For example, in thisembodiment electrically insulating separator layer 43 comprisesmicroporous separator material in the region between opposing lateralsurfaces 61, 62 of members 21, 22, respectively and between opposinglateral surfaces 63, 64 of members 21, 22, respectively. Because theprimary route for ion transfer between members 21 and members 22 occursbetween the lateral surfaces of these members, however, electricallyinsulating separator layers 86, 88 need not comprise microporousseparator material; instead, electrically insulating separator layers86, 88 may optionally comprise an electrically insulating material thatis substantially impermeable to carrier ions (e.g., lithium ions) asmore fully described in connection with FIG. 15. In one such exemplaryembodiment, electrically insulating separator layers 43, 86, and 88, incombination, surround axis A_(NE) of each member 21 for at least 70% oflength L_(NE) of each member 21. By way of further example, in one suchembodiment electrically insulating separator layers 43, 86, and 88, incombination, surround axis A_(NE) of each member 21 for at least 75% oflength L_(NE) of each member 21. By way of further example, in one suchembodiment electrically insulating separator layers 43, 86, and 88, incombination, surround axis A_(NE) of each member 21 for at least 80% oflength L_(NE) of each member 21. By way of further example, in one suchembodiment electrically insulating separator layers 43, 86, and 88, incombination, surround axis A_(NE) of each member 21 for at least 85% oflength L_(NE) of each member 21. By way of further example, in one suchembodiment electrically insulating separator layers 43, 86, and 88, incombination, surround axis A_(NE) of each member 21 for at least 90% oflength L_(NE) of each member 21. By way of further example, in one suchembodiment electrically insulating separator layers 43, 86, and 88, incombination, surround axis A_(NE) of each member 21 for at least 95% oflength L_(NE) of each member 21. By way of further example, in one suchembodiment electrically insulating separator layers 43, 86, and 88, incombination, surround axis A_(NE) of each member 21 for the entirety oflength L_(NE) of each member 21.

Referring now to FIG. 17, in one alternative embodiment electricallyinsulating separator layers 43, 86, and 88, in combination, surroundaxis A_(PE) of each member 22 of the population of positive electrodes.In this embodiment electrically insulating separator layer 43 is betweenmembers 22 of the population of positive electrodes and members 21 ofthe population of negative electrodes and electrically insulatingseparator layers 86 and 88 are elsewhere. For example, in thisembodiment electrically insulating separator layer 43 comprisesmicroporous separator material in the region between opposing lateralsurfaces 61, 62 of members 21, 22, respectively and between opposinglateral surfaces 63, 64 of members 21, 22, respectively. Because theprimary route for ion transfer between members 21 and members 22 occursbetween the lateral surfaces of these members, however, electricallyinsulating separator layers 86, 88 need not comprise microporousseparator material; instead, electrically insulating separator layers86, 88 may optionally comprise an electrically insulating material thatis substantially impermeable to carrier ions (e.g., lithium ions) asmore fully described in connection with FIG. 15. In one such exemplaryembodiment, electrically insulating separator layers 43, 86, and 88, incombination, surround axis A_(PE) of each member 22 for at least 70% oflength L_(PE) of each member 22. By way of further example, in one suchembodiment electrically insulating separator layers 43, 86, and 88, incombination, surround axis A_(PE) of each member 22 for at least 75% oflength L_(PE) of each member 22. By way of further example, in one suchembodiment electrically insulating separator layers 43, 86, and 88, incombination, surround axis A_(PE) of each member 22 for at least 80% oflength L_(PE) of each member 22. By way of further example, in one suchembodiment electrically insulating separator layers 43, 86, and 88, incombination, surround axis A_(PE) of each member 22 for at least 85% oflength L_(PE) of each member 22. By way of further example, in one suchembodiment electrically insulating separator layers 43, 86, and 88, incombination, surround axis A_(PE) of each member 22 for at least 90% oflength L_(PE) of each member 22. By way of further example, in one suchembodiment electrically insulating separator layers 43, 86, and 88, incombination, surround axis A_(PE) of each member 22 for at least 95% oflength L_(PE) of each member 22. By way of further example, in one suchembodiment electrically insulating separator layers 43, 86, and 88, incombination, surround axis A_(PE) of each member 22 for the entirety oflength L_(PE) of each member 22.

Referring now to FIG. 18, in one alternative embodiment electricallyinsulating separator layers 43, 86, and 88, in combination, surround (i)axis A_(NE) of each member 21 of the population of negative electrodesand (ii) axis A_(PE) of each member 22 of the population of positiveelectrodes. As described in connection with FIG. 15, electricallyinsulating separator layer 43 comprises microporous separator materialin the region between opposing lateral surfaces 61, 62 of members 21,22, respectively and between opposing lateral surfaces 63, 64 of members21, 22, respectively. Because the primary route for ion transfer betweenmembers 21 and members 22 occurs between the lateral surfaces of thesemembers, electrically insulating separator layers 86, 88 may compriseany electrically insulating material suitable for use in a secondarybattery; in one such embodiment, electrically insulating separatorlayers 86, 88 comprise an electrically insulating material that issubstantially impermeable to carrier ions (e.g., lithium ions) asdescribed in connection with FIG. 15. In this embodiment, electricallyinsulating separator layer 86 extends beyond front surfaces 65, 66 ofmembers 21, 22, respectively, and into the region between opposinglateral surfaces 61, 62 and opposing lateral surfaces 63, 64 of members21 and 22, respectively. Electrically insulating separator layer 88 alsoextends beyond back surfaces 67, 68 of members 21, 22, respectively, andinto the region between opposing lateral surfaces 61, 62 and opposinglateral surfaces 63, 64 of members 21 and 22, respectively. In one suchembodiment, for example, and ignoring the porosity of the microporousseparator material, the microporous separator material constitutes atleast 70 vol % of electrically insulating separator material layer 43between opposing lateral surfaces 61, 62 and opposing lateral surfaces63, 64 of members 21 and 22, respectively. By way of further example, inone embodiment and ignoring the porosity of the microporous separatormaterial, the microporous separator material constitutes at least 75 vol% of electrically insulating separator material layer 43 betweenopposing lateral surfaces 61, 62 and opposing lateral surfaces 63, 64 ofmembers 21 and 22, respectively. By way of further example, in oneembodiment and ignoring the porosity of the microporous separatormaterial, the microporous separator material constitutes at least 80 vol% of electrically insulating separator material layer 43 betweenopposing lateral surfaces 61, 62 and opposing lateral surfaces 63, 64 ofmembers 21 and 22, respectively. By way of further example, in oneembodiment and ignoring the porosity of the microporous separatormaterial, the microporous separator material constitutes at least 85 vol% of electrically insulating separator material layer 43 betweenopposing lateral surfaces 61, 62 and opposing lateral surfaces 63, 64 ofmembers 21 and 22, respectively. By way of further example, in oneembodiment and ignoring the porosity of the microporous separatormaterial, the microporous separator material constitutes at least 90 vol% of electrically insulating separator material layer 43 betweenopposing lateral surfaces 61, 62 and opposing lateral surfaces 63, 64 ofmembers 21 and 22, respectively. By way of further example, in oneembodiment and ignoring the porosity of the microporous separatormaterial, the microporous separator material constitutes at least 95 vol% of electrically insulating separator material layer 43 betweenopposing lateral surfaces 61, 62 and opposing lateral surfaces 63, 64 ofmembers 21 and 22, respectively.

Referring now to FIG. 19, in one embodiment, electrically insulatingseparator layers 43, 82 and 84 surround each member 22 and each member21 of the population of positive and negative electrodes, respectively.In this embodiment, however, electrically insulating separator layer 43surrounds axes A_(PE) and A_(NE) of each member 22 and each member 21for a fraction of lengths L_(PE) and L_(NE) of members 22 and 21,respectively. Stated differently, in this embodiment electricallyinsulating separator layer 43 is in the region between opposing lateralsurfaces of each member 21, 22, electrically insulating separator layer43 covers front surfaces 65, 66 of each member 21, 22 (see FIG. 3), andelectrically insulating separator layer 43 covers back surfaces 67, 68of each member 21, 22 (see FIG. 3), electrically insulating separatorlayer 82 is in the region between top 33 of negative electrode 21 andpositive electrode bus bar 24, and electrically insulating separatorlayer 84 is in the region between top 34 of positive electrode 22 andnegative electrode bus bar 23. Length L₈₂ corresponds to the length ofelectrically insulating separator layer 82, length L₈₄ corresponds tothe length of electrically insulating separator layer 84 and L₄₃corresponds to the length of electrically insulating separator layer 43.For example, in this embodiment electrically insulating separator layer43 surrounds (i) axis A_(NE) of each member 21 of the population ofnegative electrodes for at least a majority (e.g., at least 70%, atleast 75%, at least 80%, at least 85%, at least 90% or even at least95%) but less than the entirety of length L_(NE) of each member 21 ofthe negative electrode population. Stated differently, in thisembodiment, length L₄₃ is at least 70%, at least 75%, at least 80%, atleast 85%, at least 90% or even at least 95% but less than the entiretyof length L_(NE). Additionally, in this embodiment axis A_(PE) of eachmember 22 of the population of positive electrodes for at least amajority (e.g., at least 70%, at least 75%, at least 80%, at least 85%,at least 90% or even at least 95%) but less than the entirety of lengthL_(PE) of each member 22 of the positive electrode population. Stateddifferently, in this embodiment, length L₄₃ is at least 70%, at least75%, at least 80%, at least 85%, at least 90% or even at least 95% butless than the entirety of length L_(PE). Electrically insulatingseparator layer 43 comprises microporous separator material (aspreviously described). Because the primary route for ion transferbetween members 21 and members 22 occurs between the lateral surfaces ofthese members, however, electrically insulating separator layers 82, 84need not comprise microporous separator material; instead, electricallyinsulating separator layers 82, 84 may optionally comprise anelectrically insulating material that is substantially impermeable tocarrier ions (e.g., lithium ions) as more fully described in connectionwith FIG. 15.

In alternative embodiments, electrically insulating separator layer 82is in the region between top 33 of negative electrode 21 and positiveelectrode bus bar 24, and electrically insulating separator layer 84 isin the region between top 34 of positive electrode 22 and negativeelectrode bus bar 23 as described more fully in connection with FIG. 19,but between these two regions members 21 and 22 may be electricallyisolated along their lengths as more fully described in connection withFIGS. 12-Z. Stated differently, in on such alternative embodimentmembers 21 are surrounded by electrically insulating separator materialbut members 22 are not as more fully described in connection with FIGS.12 and 13. In another such alternative embodiment, members 22 aresurrounded by electrically insulating separator material but members 21are not as more fully described in connection with FIG. 14. In anothersuch alternative embodiment, members 21 and 22 are surrounded byelectrically insulating separator 43, 86 and 88 as more fully describedin connection with FIG. 15. In another such alternative embodiment,members 21 are surrounded by electrically insulating separator material43, 86 and 88 but not members 22 are not as more fully described inconnection with FIG. 16. In another such alternative embodiment, members22 are surrounded by electrically insulating separator material 43, 86and 88 but not members 21 are not as more fully described in connectionwith FIG. 17. In another such alternative embodiment, members 21 and 22are surrounded by electrically insulating separator 43, 86 and 88 asmore fully described in connection with FIG. 18. In each of theseembodiments, length L₄₃ is at least 70%, at least 75%, at least 80%, atleast 85%, at least 90% or even at least 95% but less than the entiretyof length L_(PE) and/or L_(NE).

Referring now to FIG. 20, in one alternative embodiment, negativeelectrode active material layer 49 is between negative electrodebackbone 51 and negative electrode current collector layer 47. In thisembodiment, negative electrode current collector layer 47 comprises anionically permeable conductor material that is both ionically andelectrically conductive. Stated differently, negative electrode currentcollector layer 47 has a thickness, an electrical conductivity, and anionic conductivity for carrier ions that facilitates the movement ofcarrier ions between an immediately adjacent negative electrode activematerial layer 49 on one side of the ionically permeable conductor layerand an immediately adjacent electrically insulating separator layer 43on the other side of the negative electrode current collector layer inan electrochemical stack. On a relative basis, the negative electrodecurrent collector layer has an electrical conductance that is greaterthan its ionic conductance when there is an applied current to storeenergy in the device or an applied load to discharge the device. Forexample, the ratio of the electrical conductance to the ionicconductance (for carrier ions) of the negative electrode currentcollector layer will typically be at least 1,000:1, respectively, whenthere is an applied current to store energy in the device or an appliedload to discharge the device. By way of further example, in one suchembodiment the ratio of the electrical conductance to the ionicconductance (for carrier ions) of the negative electrode currentcollector layer is at least 5,000:1, respectively, when there is anapplied current to store energy in the device or an applied load todischarge the device. By way of further example, in one such embodimentthe ratio of the electrical conductance to the ionic conductance (forcarrier ions) of the negative electrode current collector layer is atleast 10,000:1, respectively, when there is an applied current to storeenergy in the device or an applied load to discharge the device. By wayof further example, in one such embodiment the ratio of the electricalconductance to the ionic conductance (for carrier ions) of the negativeelectrode current collector layer is at least 50,000:1, respectively,when there is an applied current to store energy in the device or anapplied load to discharge the device. By way of further example, in onesuch embodiment the ratio of the electrical conductance to the ionicconductance (for carrier ions) of the negative electrode currentcollector layer is at least 100,000:1, respectively, when there is anapplied current to store energy in the device or an applied load todischarge the device.

In general, when negative electrode current collector layer 47 is anionically permeable conductor layer, it will have a thickness of atleast about 300 Angstroms. For example, in some embodiments it may havea thickness in the range of about 300-800 Angstroms. More typically,however, it will have a thickness greater than about 0.1 micrometers. Ingeneral, an ionically permeable conductor layer will have a thicknessnot greater than about 100 micrometers. Thus, for example, in oneembodiment, negative electrode current collector layer 47 will have athickness in the range of about 0.1 to about 10 micrometers. By way offurther example, in some embodiments, negative electrode currentcollector layer 47 will have a thickness in the range of about 0.1 toabout 5 micrometers. By way of further example, in some embodiments,negative electrode current collector layer 47 will have a thickness inthe range of about 0.5 to about 3 micrometers. In general, it ispreferred that the thickness of negative electrode current collectorlayer 47 be approximately uniform. For example, in one embodiment it ispreferred that negative electrode current collector layer 47 have athickness non-uniformity of less than about 25% wherein thicknessnon-uniformity is defined as the quantity of the maximum thickness ofthe layer minus the minimum thickness of the layer, divided by theaverage layer thickness. In certain embodiments, the thickness variationis even less. For example, in some embodiments negative electrodecurrent collector layer 47 has a thickness non-uniformity of less thanabout 20%. By way of further example, in some embodiments negativeelectrode current collector layer 47 has a thickness non-uniformity ofless than about 15%. In some embodiments the ionically permeableconductor layer has a thickness non-uniformity of less than about 10%.

In those embodiments in which negative electrode current collector layer47 comprises an ionically permeable conductor material that is bothionically and electrically conductive, negative electrode currentcollector layer 47 may have an ionic conductance that is comparable tothe ionic conductance of an adjacent electrically insulating separatorlayer 43 when a current is applied to store energy in the device or aload is applied to discharge the device, such as when a secondarybattery is charging or discharging. For example, in one embodimentnegative electrode current collector layer 47 has an ionic conductance(for carrier ions) that is at least 50% of the ionic conductance of theseparator layer (i.e., a ratio of 0.5:1, respectively) when there is anapplied current to store energy in the device or an applied load todischarge the device. By way of further example, in some embodiments theratio of the ionic conductance (for carrier ions) of negative electrodecurrent collector layer 47 to the ionic conductance (for carrier ions)of the separator layer is at least 1:1 when there is an applied currentto store energy in the device or an applied load to discharge thedevice. By way of further example, in some embodiments the ratio of theionic conductance (for carrier ions) of negative electrode currentcollector layer 47 to the ionic conductance (for carrier ions) of theseparator layer is at least 1.25:1 when there is an applied current tostore energy in the device or an applied load to discharge the device.By way of further example, in some embodiments the ratio of the ionicconductance (for carrier ions) of negative electrode current collectorlayer 47 to the ionic conductance (for carrier ions) of the separatorlayer is at least 1.5:1 when there is an applied current to store energyin the device or an applied load to discharge the device. By way offurther example, in some embodiments the ratio of the ionic conductance(for carrier ions) of negative electrode current collector layer 47 tothe ionic conductance (for carrier ions) of the separator layer is atleast 2:1 when there is an applied current to store energy in the deviceor an applied load to discharge the device.

In one embodiment, negative electrode current collector layer 47 alsohas an electrical conductance that is substantially greater than theelectrical conductance of negative electrode active material layer 49.For example, in one embodiment the ratio of the electrical conductanceof negative electrode current collector layer 47 to the electricalconductance of negative electrode active material layer 49 is at least100:1 when there is an applied current to store energy in the device oran applied load to discharge the device. By way of further example, insome embodiments the ratio of the electrical conductance of negativeelectrode current collector layer 47 to the electrical conductance ofthe negative electrode active material layer is at least 500:1 whenthere is an applied current to store energy in the device or an appliedload to discharge the device. By way of further example, in someembodiments the ratio of the electrical conductance of negativeelectrode current collector layer 47 to the electrical conductance ofthe negative electrode active material layer is at least 1000:1 whenthere is an applied current to store energy in the device or an appliedload to discharge the device. By way of further example, in someembodiments the ratio of the electrical conductance of negativeelectrode current collector layer 47 to the electrical conductance ofthe negative electrode active material layer is at least 5000:1 whenthere is an applied current to store energy in the device or an appliedload to discharge the device. By way of further example, in someembodiments the ratio of the electrical conductance of negativeelectrode current collector layer 47 to the electrical conductance ofthe negative electrode active material layer is at least 10,000:1 whenthere is an applied current to store energy in the device or an appliedload to discharge the device.

The thickness of negative electrode current collector layer 47 (i.e.,the shortest distance between the separator and the negative electrodeactive material layer between which ionically permeable negativeelectrode current collector layer 47 is sandwiched) in this embodimentwill depend upon the composition of the layer and the performancespecifications for the electrochemical stack. In general, when anegative electrode current collector layer is an ionically permeableconductor layer, it will have a thickness of at least about 300Angstroms. For example, in some embodiments it may have a thickness inthe range of about 300-800 Angstroms. More typically, however, it willhave a thickness greater than about 0.1 micrometers. In general, anionically permeable conductor layer will have a thickness not greaterthan about 100 micrometers. Thus, for example, in one embodiment,negative electrode current collector layer 47 will have a thickness inthe range of about 0.1 to about 10 micrometers. By way of furtherexample, in some embodiments, negative electrode current collector layer47 will have a thickness in the range of about 0.1 to about 5micrometers. By way of further example, in some embodiments, negativeelectrode current collector layer 47 will have a thickness in the rangeof about 0.5 to about 3 micrometers. In general, it is preferred thatthe thickness of negative electrode current collector layer 47 beapproximately uniform. For example, in one embodiment it is preferredthat negative electrode current collector layer 47 have a thicknessnon-uniformity of less than about 25% wherein thickness non-uniformityis defined as the quantity of the maximum thickness of the layer minusthe minimum thickness of the layer, divided by the average layerthickness. In certain embodiments, the thickness variation is even less.For example, in some embodiments negative electrode current collectorlayer 47 has a thickness non-uniformity of less than about 20%. By wayof further example, in some embodiments negative electrode currentcollector layer 47 has a thickness non-uniformity of less than about15%. In some embodiments the ionically permeable conductor layer has athickness non-uniformity of less than about 10%.

In one preferred embodiment, negative electrode current collector layer47 is an ionically permeable conductor layer comprising an electricallyconductive component and an ion conductive component that contribute tothe ionic permeability and electrical conductivity. Typically, theelectrically conductive component will comprise a continuouselectrically conductive material (such as a continuous metal or metalalloy) in the form of a mesh or patterned surface, a film, or compositematerial comprising the continuous electrically conductive material(such as a continuous metal or metal alloy). Additionally, the ionconductive component will typically comprise pores, e.g., interstices ofa mesh, spaces between a patterned metal or metal alloy containingmaterial layer, pores in a metal film, or a solid ion conductor havingsufficient diffusivity for carrier ions. In certain embodiments, theionically permeable conductor layer comprises a deposited porousmaterial, an ion-transporting material, an ion-reactive material, acomposite material, or a physically porous material. If porous, forexample, the ionically permeable conductor layer may have a voidfraction of at least about 0.25. In general, however, the void fractionwill typically not exceed about 0.95. More typically, when the ionicallypermeable conductor layer is porous the void fraction may be in therange of about 0.25 to about 0.85. In some embodiments, for example,when the ionically permeable conductor layer is porous the void fractionmay be in the range of about 0.35 to about 0.65.

Being positioned between negative electrode active material layer 49 andelectrically insulating separator layer 43, negative electrode currentcollector layer 47 may facilitate more uniform carrier ion transport bydistributing current from the negative electrode current collectoracross the surface of the negative electrode active material layer.This, in turn, may facilitate more uniform insertion and extraction ofcarrier ions and thereby reduce stress in the negative electrode activematerial during cycling; since negative electrode current collectorlayer 47 distributes current to the surface of the negative electrodeactive material layer facing the separator, the reactivity of thenegative electrode active material layer for carrier ions will be thegreatest where the carrier ion concentration is the greatest.

Referring now to FIG. 21, in an alternative embodiment, positiveelectrode active material layer 50 is between positive electrodebackbone 52 and positive electrode current collector layer 48. In thisembodiment, positive electrode current collector layer 48 comprises anionically permeable conductor material that is both ionically andelectrically conductive. Stated differently, the positive electrodecurrent collector layer has a thickness, an electrical conductivity, andan ionic conductivity for carrier ions that facilitates the movement ofcarrier ions between an immediately adjacent positive electrode activematerial layer 50 on one side of the ionically permeable conductor layerand an immediately adjacent electrically insulating separator layer 43on the other side of the positive electrode current collector layer inan electrochemical stack. On a relative basis in this embodiment, thepositive electrode current collector layer has an electrical conductancethat is greater than its ionic conductance when there is an appliedcurrent to store energy in the device or an applied load to dischargethe device. For example, the ratio of the electrical conductance to theionic conductance (for carrier ions) of the positive electrode currentcollector layer will typically be at least 1,000:1, respectively, whenthere is an applied current to store energy in the device or an appliedload to discharge the device. By way of further example, in one suchembodiment the ratio of the electrical conductance to the ionicconductance (for carrier ions) of the positive electrode currentcollector layer is at least 5,000:1, respectively, when there is anapplied current to store energy in the device or an applied load todischarge the device. By way of further example, in one such embodimentthe ratio of the electrical conductance to the ionic conductance (forcarrier ions) of the positive electrode current collector layer is atleast 10,000:1, respectively, when there is an applied current to storeenergy in the device or an applied load to discharge the device. By wayof further example, in one such embodiment the ratio of the electricalconductance to the ionic conductance (for carrier ions) of the positiveelectrode current collector layer is at least 50,000:1, respectively,when there is an applied current to store energy in the device or anapplied load to discharge the device. By way of further example, in onesuch embodiment the ratio of the electrical conductance to the ionicconductance (for carrier ions) of the positive electrode currentcollector layer is at least 100,000:1, respectively, when there is anapplied current to store energy in the device or an applied load todischarge the device.

Referring now to FIG. 22, in one alternative embodiment, negativeelectrode active material layer 49 is between negative electrodebackbone 51 and negative electrode current collector layer 47 andpositive electrode active material layer 50 is between positiveelectrode backbone 52 and positive electrode current collector layer 48.In this embodiment, negative electrode current collector layer 47 andpositive electrode current collector layer 48 comprise an ionicallypermeable conductor material that is both ionically and electricallyconductive. Stated differently, the negative electrode current collectorlayer and the positive electrode current collector layer each have athickness, an electrical conductivity, and an ionic conductivity forcarrier ions that facilitates the movement of carrier ions between animmediately adjacent positive electrode active material layer 50 and anegative electrode active material layer 49. On a relative basis in thisembodiment, the positive electrode current collector layer and thenegative electrode current collector layers each have an electricalconductance that is greater than its ionic conductance when there is anapplied current to store energy in the device or an applied load todischarge the device as previously described. For example, the ratio ofthe electrical conductance to the ionic conductance (for carrier ions)of the positive electrode current collector layer and the negativeelectrode current collector layer in this embodiment will typically beat least 1,000:1, respectively, when there is an applied current tostore energy in the device or an applied load to discharge the device.

Referring now to FIGS. 21 and 22, in one alternative embodiment negativeelectrode 21 comprises negative electrode backbone 51, negativeelectrode active material layer 49, negative electrode current collectorlayer 47 and supplemental negative electrode current collector layers47A, 47B and positive electrode 22 comprises positive electrode backbone52, positive electrode active material layer 50, positive electrodecurrent collector layer 48 and supplemental positive electrode currentcollector layers 48A, 48B. Supplemental negative electrode currentcollectors may be incorporated into the negative electrode populationmembers and/or the positive electrode population members to provideadditional electrical conductance.

In certain embodiments, the supplemental negative electrode currentcollector has an electrical conductance that exceeds the electricalconductance of the negative electrode current collector by a factor ofat least 2; in certain embodiments, the electrical conductance of thesupplemental negative electrode current collector exceeds the electricalconductance of the negative electrode current collector by a factor ofat least 5 or even 10. Advantageously, the additional electricalconductance provided by the supplemental negative electrode currentcollector allows the overall current collector weight and volumerequirement of the negative electrode current collector layer 47.Additionally, when the negative electrode current collector layer is anionically permeable current collector (as described more fully elsewhereherein), the supplemental negative electrode current collector currentcollector may carry the majority of the current along the electrodelength L_(NE) and the negative electrode current collector layer canfunction to primarily collect the current from the electrode and provideit to the supplemental negative electrode current collector. This inturn reduces the electronic conductance required from the ionicallypermeable current collector layer, and allows for the ability to designthe ionically permeable layer to have a lower electronic conductivityand higher ionic conductivity for better cell performance.

Referring now to FIG. 23, in one embodiment negative electrode currentconductor layer 47 comprised by each member 21 of the negative electrodepopulation has length L_(NC) that is at least 50% of the length L_(NE)of the member comprising such negative electrode current collector. Byway of further example, in one embodiment negative electrode currentconductor layer 47 comprised by each member 21 of the negative electrodepopulation has a length L_(NC) that is at least 60% of the length L_(NE)of the member comprising such negative electrode current collector. Byway of further example, in one embodiment the negative electrode currentconductor layer 47 comprised by each member 21 of the negative electrodepopulation has a length L_(NC) that is at least 70% of the length L_(NE)of the member comprising such negative electrode current collector. Byway of further example, in one embodiment negative electrode currentconductor layer 47 comprised by each member 21 of the negative electrodepopulation has a length L_(NC) that is at least 80% of the length L_(NE)of the member comprising such negative electrode current collector. Byway of further example, in one embodiment negative electrode currentconductor layer 47 comprised by each member 21 of the negative electrodepopulation has a length L_(NC) that is at least 90% of length L_(NE) ofthe member comprising such negative electrode current collector.

In some embodiments, the supplemental negative electrode currentcollector can provide a means for blocking the charge/dischargereactions at certain locations along the electrode. Supplemental currentcollectors 47A, 47B can be designed such that the ionic conductivity ofthis layer is essentially zero, which inhibits the charge/dischargereaction on the electrode that is directly under the supplementalcurrent collector.

In each of the foregoing embodiments, supplemental negative electrodecurrent collector layers 47A, 47B independently have a length (measuredin the same direction as the length L_(NC)) that is the same as, asubstantial fraction of (e.g., at least 60%, at least 70%, at least 80%or even at least 90% of the length L_(NC) of the negative electrodecurrent collector layer 47. Alternatively, in each of the foregoingembodiments, supplemental negative electrode current collector layers47A, 47B independently have a length (measured in the same direction asthe length L_(NC)) that is less than a substantial fraction of (e.g.,less than 40%, 30%, 20% or even 10% of the length L_(NC) of the negativeelectrode current collector layer 47. Length L_(NE) of each of themembers 21 of the negative electrode population will vary depending uponthe energy storage device and its intended use, but in many embodimentswill be within the range of about 5 mm to about 500 mm. For example, inone embodiment, length L_(NE) for each of member 21 will be within therange of about 10 mm to about 250 mm. By way of further example, in oneembodiment, length L_(NE) for each of member 21 will be in the range ofabout 25 mm to about 100 mm.

Supplemental negative electrode current collector layers 47A and 47B maycomprise any of the materials previously identified in connection withnegative electrode current collector layer 47. Because supplementalnegative electrode current collector layers 47A and 47B are not betweenthe negative and positive electrode active material layers, they neednot be ionically permeable to carrier ions. Thus, supplemental negativeelectrode current collector layers 47A, 47B may comprise any metal orother conductor conventionally used as a current collector material fornegative electrodes such as carbon, cobalt, chromium, copper, nickel,titanium, or an alloy of one or more thereof. Additionally, in oneembodiment, supplemental negative electrode current collector layers47A, 47B independently have an electrical conductance that exceeds theelectrical conductance of negative electrode current collector layer 47.For example, in one embodiment, at least one of supplemental negativeelectrode current collector layers 47A, 47B has an electricalconductance that is at least 200%, e.g., at least 1000%, of theelectrical conductance of negative electrode current collector layer.

Referring now to FIG. 24, positive electrode backbone 52, positiveelectrode active material layer 50, and positive electrode currentcollector layer 48 and supplemental positive electrode current collectorlayers 48A, 48B preferably extend a majority of the distance from bottom32 to top 34 of each member 22 of the negative electrode population.Supplemental positive electrode current collectors may be incorporatedinto the positive electrode population members to provide additionalelectrical conductance. In certain embodiments, the supplementalpositive electrode current collector has an electrical conductance thatexceeds the electrical conductance of the positive electrode currentcollector by a factor of at least 2; in certain embodiments, theelectrical conductance of the supplemental positive electrode currentcollector exceeds the electrical conductance of the positive electrodecurrent collector by a factor of at least 5 or even 10. Advantageously,the additional electrical conductance provided by the supplementalpositive electrode current collector allows the overall currentcollector weight and volume requirement of the positive electrodecurrent collector layer 48 to be reduced. Additionally, when thepositive electrode current collector layer is an ionically permeablecurrent collector (as described more fully elsewhere herein), thesupplemental positive electrode current collector may carry the majorityof the current along the electrode length L_(PE) and the positiveelectrode current collector layer can function to primarily collect thecurrent from the electrode and provide it to the supplemental positiveelectrode current collector. This in turn reduces the electronicconductance required from the ionically permeable current collectorlayer, and allows for the ability to design the ionically permeablelayer to have a lower electronic conductivity and higher ionicconductivity for better cell performance.

Supplemental positive electrode current collector layers 48A and 48B maycomprise any of the materials previously identified in connection withpositive electrode current collector layer 48. Additionally, in oneembodiment, at least one of supplemental positive electrode currentcollector layers 48A, 48B has an electrical conductance that exceeds theelectrical conductance of positive electrode current collector layer 48.For example, in one embodiment, at least one of supplemental positiveelectrode current collector layers 48A, 48B has an electricalconductance that is at least 200-1,000% of the electrical conductance ofpositive electrode current collector layer.

In some embodiments, the supplemental positive electrode currentcollector can provide a means for blocking the charge/dischargereactions at certain locations along the electrode. Supplemental currentcollectors 48A, 48B can be designed such that the ionic conductivity ofthis layer is essentially zero, which inhibits the charge/dischargereaction on the electrode that is directly under the supplementalcurrent collector.

For example, in one embodiment the positive electrode current conductorlayer 48 comprised by each member 22 of the positive electrodepopulation has a length L_(PC) that is at least 50% of the length L_(PE)of the member comprising such positive electrode current collector. Byway of further example, in one embodiment the positive electrode currentconductor layer 48 comprised by each member 22 of the positive electrodepopulation has a length L_(PC) that is at least 60% of the length L_(PE)of the member comprising such positive electrode current collector. Byway of further example, in one embodiment the positive electrode currentconductor layer 48 comprised by each member 22 of the positive electrodepopulation has a length L_(PC) that is at least 70% of the length L_(PE)of the member comprising such positive electrode current collector. Byway of further example, in one embodiment the positive electrode currentconductor layer 48 comprised by each member 22 of the positive electrodepopulation has a length L_(PC) that is at least 80% of the length L_(PE)of the member comprising such positive electrode current collector. Byway of further example, in one embodiment the positive electrode currentconductor layer 48 comprised by each member 22 of the positive electrodepopulation has a length L_(PC) that is at least 90% of the length L_(PE)of the member comprising such positive electrode current collector. Ineach of the foregoing embodiments, the supplemental positive electrodecurrent collector layers 48A, 48B independently have a length (measuredin the same direction as the length L_(PC)) that is the same as, asubstantial fraction of (e.g., at least 60%, at least 70%, at least 80%or even at least 90% of the length L_(PC) of the positive electrodecurrent collector layer 48. Alternatively, in each of the foregoingembodiments, the supplemental positive electrode current collectorlayers 48A, 48B independently have a length (measured in the samedirection as the length L_(PC)) that is less than a substantial fractionof (e.g., less than 40%, less than 30%, less than 20% or even less than10% of the length L_(PC) of the positive electrode current collectorlayer 48. The length L_(PE) of each of the members 22 of the positiveelectrode population will vary depending upon the energy storage deviceand its intended use, but in many embodiments will be within the rangeof about 5 mm to about 500 mm. For example, in one embodiment, lengthL_(PE) for each of member 21 will be within the range of about 10 mm toabout 250 mm. By way of further example, in one embodiment, lengthL_(PE) for each of member 21 will be in the range of about 25 mm toabout 100 mm.

Supplemental negative electrode current collector layers 47A, 47B and/orsupplemental positive electrode current collector layers 48A, 48B mayprovide improved rate performance in certain embodiments. Thesupplemental positive and/or negative current collectors may be formedon the electrode structure using similar methods as those described inconnection with the formation of the positive and negative electrodecurrent collectors. Known methods for masking and patterning may be usedto prepare the backbones for selectively depositing the supplementalcurrent collectors at the desired areas. In some instances, thedeposition of the current collector would be performed after the activeelectrode is deposited in order to provide an ionically permeablecurrent collection scheme.

Referring again to FIGS. 4 and 5, in certain embodiments members 21 ofthe negative electrode population will have straight sides (i.e., eachof the sides extending between bottom 31 and top 33 is planar). In otherembodiments, the negative electrode population members will have sidesthat are polygonal or even curved (e.g., the sides extending betweenbottom 31 and top 33 may be sinusoidal). In each such embodiment, lengthL_(NE) is the straight-line distance between bottom 31 and top 33.

Referring again to FIGS. 4 and 6, in certain embodiments members 22 ofthe positive electrode population will have straight sides (i.e., eachof the sides extending between bottom 32 and top 34 is planar). In otherembodiments, the positive electrode population members will have sidesthat are polygonal or even curved (e.g., the sides extending betweenbottom 32 and top 34 may be sinusoidal). In each such embodiment, lengthL_(PE) is the straight-line distance between bottom 32 and top 34.

In the embodiment illustrated in FIG. 7, negative electrode populationmembers 21 have a constant width W_(NE) and a constant height H_(NE) asa function of length. In other embodiments, the negative electrodepopulation members 21 may have a width W_(NE) or height H_(NE) thatvaries as a function of position along the negative electrode length orthe negative electrode population members may have a cross-section(taken in a plane that is normal to the length direction) that is otherthan rectangular. In such other embodiments, width W_(NE) and heightH_(NE) refer to the maximum width and the maximum height of a projectionof the negative electrode population members 21 in a plane that isnormal to the length direction of the negative electrode populationmembers 21. Stated differently, width W_(NE) and height H_(NE)correspond to the lengths of two adjacent sides of an imaginaryrectangle lying in the plane that has the smallest dimensions but yetcontains all of the points of the projection of the negative electrodepopulation members.

In the embodiment illustrated in FIG. 8, positive electrode populationmembers 22 have a constant width W_(PE) and a constant height H_(PE) asa function of length. In other embodiments, the negative electrodepopulation members 22 may have a width W_(PE) or height H_(PE) thatvaries as a function of position along the negative electrode length orthe negative electrode population members may have a cross-section(taken in a plane that is normal to the length direction) that is otherthan rectangular. In such other embodiments, width W_(PE) and heightH_(PE) refer to the maximum width and the maximum height of a projectionof the positive electrode population members 22 in a plane that isnormal to the length direction of the positive electrode populationmembers 22. Stated differently, width W_(PE) and height H_(PE)correspond to the lengths of two adjacent sides of an imaginaryrectangle lying in the plane that has the smallest dimensions but yetcontains all of the points of the projection of the positive electrodepopulation members.

FIGS. 25A-E illustrative several alternative projections of an electrode(positive or negative electrode) in a plane that is normal to the lengthdirection of the electrode. In FIGS. 25A-E, the projection of theelectrode traces a trapezoid (FIG. 25A), a parallelogram (FIG. 25B), atriangle (FIG. 25C), a diamond (FIG. 25D), and an oval (FIG. 25E). Ineach instance, an imaginary rectangle having the smallest dimensions butyet containing all of the points of the projection of the electrodewould have width W_(E) and height H_(E). In addition, in each of theseinstances, the electrode would have a perimeter P_(E) corresponding tothe circumference to the geometric figure traced by the projection.

Referring now to FIG. 26, in one alternative embodiment an electrodestack 74 comprises three electrode structures 20 stacked vertically andaligned such that positive electrodes 22 of the three electrodes arealigned and negative electrode structures 21 are aligned. In thisembodiment, electrically insulating material layer 86 covers frontsurfaces 65, 66 of members 21, 22 of the top electrode structure in thestack and electrically insulating material layer 88 covers back surfaces67, 68 of members 21, 22 of the bottom electrode structure in the stack.As a result, members 21 of different electrode structure are notelectrically isolated from each other, but they are electricallyisolated from members 22 of the different electrode structures in thestack. As a result, each positive electrode structure 22 is surroundedby electrically insulating material layers 43, 86 and 88 and eachnegative electrode structure 21 is surrounded by electrically insulatinglayers 43, 86, and 88. For ease of illustration, electrode stack 74comprises only three electrode structures. As described in connectionwith FIG. 10, electrode stack 74 may comprise a lesser or greater numberof electrode structures 20.

Referring now to FIG. 27, in one alternative embodiment an electrodestack 74 comprises three electrode structures 20 stacked vertically andaligned such that a member 22 of the population of positive electrodesof an electrode structure is aligned with and above and/or below amember 21 of the population of negative electrodes of another electrodestructure 20. In this embodiment, each member 21 and each member 22 issurrounded by electrically insulating layer 43. For ease ofillustration, electrode stack 74 comprises only three electrodestructures. As described in connection with FIG. 10, electrode stack 74may comprise a lesser or greater number of electrode structures 20.

The following non-limiting examples are provided to further illustratethe present invention.

EXAMPLES Example 1 3D Single Cell Fabrication 1

1. Comb Structure Fabrication

A silicon on insulator (SOI) wafer with a layer thickness of 200 μm/3μm/675 μm (device layer/insulating layer/backing layer) was used as thesample. 1000 Å of Pd was sputter deposited on top of the device layerfollowed by a hard mask layer of 2000 Å silicon dioxide.

This wafer was then spin coated with 5 μm of resist and patterned with amask to obtain a comb shaped structure with two interdigitated combsisolated from each other.

The design shows a structure that results in two independent comb shapestructures with each structure terminating in a landing pad suitable formaking electrical contact. The gap between the adjacent waves wasdesigned at 100 microns. The length of each of the lines was 10000microns, with an edge to edge spacing of 200 microns on either ends,i.e. between the ends of the comb and the opposing electrodeconnections. Said differently, the spacing was 200 um between the top ofnegative electrode comb consituting a part of the negative electrode 21and the bottom of the positive electrode comb constituting the positiveelectrode 22 in FIG. 9. The photoresist in this pattern was then used asa photomask to remove the silicon dioxide and Palladium by Ion Milling.

The combination of silicon dioxide, photoresist, and Pd was used as amask for Silicon removal using Deep Reactive Ion Etching (DRIE) in aFluoride plasma. The DRIE was performed until the silicon constitutingthe device layer in the mask gaps was completely removed, stopping onthe oxide layer. The overetch time used was 10% of the total DRIE timein order to remove islands of silicon in the trench floor. Any topphotoresist was removed by stripping in acetone. At this point the twocombs are electrically isolated by the DRIE.

The positive electrode pad and the negative electrode pad were aloneimmersed in dilute (5:1) Buffered Oxide Etch (BOE) solution for 1 minuteto remove the masking oxide layer in order to provide access to thepalladium metal to make electrical contact. The comb structure withisolated negative electrode combs and positive electrode combs were usedas the base structure for current collector and electrode fabrication.

2. Negative Electrode Current Collector and Negative ElectrodeFabrication

One of the isolated pair of comb-like structures (herein named thenegative electrode backbone comb) was electrically connected through thepalladium conductor and was immersed in a copper plating bath. Thecopper plating bath conditions were adjusted such that the depositionhappened on the silicon layer constituting the comb structure. This Culayer deposited thusly serves as the negative electrode currentcollector.

The sample was immersed in an electrophoretic resist bath and thepositive electrode backbone comb structure was subsequently energized. Acommercially available electrophoretic resist was used (Shipley EAGLE),and the comb was electrophoretically deposited at 50 V for 120 secondsusing the Pd conductor to form a resist coating. The die was baked at120 C for 30 min to harden the resist.

The silicon sample is now inserted into an evaporation chamber, and 20 ÅAu is deposited on the sample surface. This Au deposition processresults in Au on the top of the honeycomb structures as well as on itssidewalls, as well as on the bottom oxide layer. However, thephotoresist being present on the positive electrode backbone comb causesthe Au to be in contact with the copper on the negative electrodebackbone comb structure only. The silicon backing layer was protected atthis time by an adhesive tape mask. The sample is subsequently immersedin acetone for 15 min to remove the electrophoretic resist alongwith theevaporated Au on top of the electrophoretic resist. The sample is thenimmersed in a solution of dilute (5:1) Buffered Oxide Etch (BOE) toremove the Au clusters and the oxide layer from the front face of thenegative electrode comb and the insulating layer at the bottom of thetrench. This isolates the Au nanoclusters to the sides of the negativeelectrode backbone comb only.

Silicon nanowires are then grown on the sides of the negative electrodebackbone comb structure by CVD method. The sample is inserted into a CVDchamber and heated to 550 C. Silane gas is introduced into the chamber;the reactor pressure was kept at 10 Torr. The deposition rate was 4um/hr; and the deposition was done to a target nanowire thickness of 20um. These nanowires extending out from the sides of the negativeelectrode backbone comb was to serve as the negative electrode for thelithium-ion battery.

3. Positive Electrode Current Collector and Positive ElectrodeFabrication.

The positive electrode backbone comb was then electrically connectedthrough the palladium conductor and was immersed in a goldelectroplating bath to plate gold on the palladium and the silicon layerconstituting the comb structure. This Au layer surrounding the positiveelectrode backbone comb will serve as the positive electrode currentcollector.

The positive electrode backbone comb was electrophoretically depositedwith a lithium ion battery positive electrode material. TheElectrophoretic deposition solution contained the positive electrodematerial (LiCoO2), 15 wt % Carbon black, and 150 ppm of Iodine in asolution of acetone. The solution mixture was stirred overnight in orderto disperse the particles uniformly. The Pd contact pad was used as theterminal for electrical connection for the positive electrodedeposition. A Pt counter electrode was used. The sample was depositedfor 3 min at a voltage of 100V to deposit a 40 um thick positiveelectrode structure. The deposition occurred on both the sidewalls andthe front face of the positive electrode comb.

4. Excess Positive Electrode Removal

Any excess positive electrode that was deposited on the front face ofthe die was removed using mechanical removal processes. The front facewas lapped using a polishing pad to expose the positive electrodecurrent collector layer; followed by forced air drying to ensure noloose particles that can cause shorts are present on the die.

5. Separator Layer No. 1 Fabrication

The porous separator is applied into the gap (which is nominally 40microns) between the positive electrode and the negative electrode byusing a slurry comprising fine glass powder (<2 microns in diameter)dispersed in N-methyl pyrollidone along with a PVDF binder of 2 volumepercent with a solids content of 60% as made. This slurry is screenprinted so as to wet the die and force the particulate matter to go inbetween the negative electrode and the positive electrode materials. Thescreen printing is done in multiple passes with an intermediate dryingstep in between so as to fill the trenches between the negativeelectrode and positive electrode; and the gaps along the top and thebottom of the device (areas that constitute 82 and 84 in FIG. 19).

Any excess separator that was deposited on the front face of the die wasremoved using mechanical removal processes. The front face was lappedusing a polishing pad to expose the electrode current collector layers;followed by forced air drying to ensure no loose particles that cancause shorts are present on the die.

6. Structural Layer Removal

The top side of the die is subsequently bonded to a sacrificial glasssubstrate with the aid of a UV release dicing tape. This arrangement isused to mechanically remove the backing silicon layer using conventionalwafer lapping techniques. The lapping process is carried on until thebacking wafer and the intermediate oxide layer are removed. The UVrelease is used to remove the active die off the sacrificial glasssubstrate; thereby making the die ready for subsequent separator fillprocessing.

7. Separator Layer No. 2 Fabrication

An additional layer of porous separator is applied on the front face andthe back face of the die by dip-coating the die in a slurry comprisingfine glass powder (<2 microns in diameter) dispersed inN-methylpyrollidone along with a PVDF binder of 2 volume percent with asolids content of 30% as made. The dip coated die is dried in order toremove the solvent and solidify the binder material (at this stage, thecross section of the device looks like FIG. 15, except for the lack ofcurrent collector 47 and 48 on the bottom face of the silicon.) The dipcoating thickness on the front face and the back face was targeted to 25microns each.

Example 2 3D Single Cell Fabrication 2

1. Comb Structure Fabrication

A silicon wafer with a layer thickness of 200 μm was used as the sample.1000 Å of Pd was sputter deposited on top of the device layer followedby a hard mask layer of 2000 Å silicon dioxide. The wafer was flippedaround and 1500 Å of Cu was deposited on the bottom side.

This sample was then bonded anodically to a borofloat glass substrateusing standard anodic bonding techniques.

This wafer was then spin coated with 5 μm of resist and patterned with amask to obtain a comb shaped structure with two interdigitated combsseparated from each other as shown in FIG. 1.

The design shows a structure that results in two independent comb shapestructures with each structure terminating in a landing pad suitable formaking electrical contact. The gap between the adjacent waves wasdesigned at 100 microns. The length of each of the lines was 10000microns, with an edge to edge spacing of 200 microns on either ends,i.e. between the ends of the comb and the opposing electrodeconnections. Said differently, the spacing was 200 um between the top ofnegative electrode comb consituting a part of the negative electrode 21and the bottom of the positive electrode comb constituting the positiveelectrode 22 in FIG. 9. The photoresist in this pattern was then used asa photomask to remove the silicon dioxide and Palladium by Ion Milling.

The combination of silicon dioxide, photoresist, and Pd was used as amask for Silicon removal using Deep Reactive Ion Etching (DRIE) in aFluoride plasma. The DRIE was performed until the silicon constitutingthe device layer in the mask gaps was completely removed, stopping onthe oxide layer. The overetch time used was 10% of the total DRIE timein order to remove islands of silicon in the trench floor. Any topphotoresist was removed by stripping in acetone. The die wassubsequently dipped in 1% nitric acid solution to remove the copper atthe bottom of the trenches and expose the anodic glass. At this pointthe two combs are electrically isolated by the DRIE.

The positive electrode pad and the negative electrode pad were aloneimmersed dilute (5:1) Buffered Oxide Etch (BOE) solution for 1 minute toremove the masking oxide layer in order to provide access to thepalladium metal to make electrical contact. The comb structure withisolated negative electrode combs and positive electrode combs were usedas the base structure for current collector and electrode fabrication.

2. Negative Electrode Current Collector and Negative ElectrodeFabrication

The negative electrode current collector and negative electrodes werefabricated with a process similar to Example 1.

3. Positive Electrode Current Collector and Positive ElectrodeFabrication.

The positive electrode current collector and positive electrodes werefabricated with a process similar to Example 1.

4. Separator Fabrication.

The porous separator is applied into the gap (which is nominally 40microns) between the positive electrode and the negative electrode byusing a slurry comprising fine glass powder (<2 microns in diameter)dispersed in N-methyl pyrollidone along with a PVDF binder of 2 volumepercent with a solids content of 60% as made. This slurry is screenprinted so as to wet the die and force the particulate matter to go inbetween the negative electrode and the positive electrode materials. Thescreen printing is done in multiple passes with an intermediate dryingstep in between so as to fill the trenches between the negativeelectrode and positive electrode; and the gaps along the top and thebottom of the device (areas that constitute 82 and 84 in FIG. 19).Subsequently, The porous separator is also applied on the front face ofthe die by dip-coating the die in a slurry comprising fine glass powder(<2 microns in diameter) dispersed in N-methylpyrollidone along with aPVDF binder of 2 volume percent with a solids content of 30% as made.The dip coated die is dried in order to remove the solvent and solidifythe binder material. The dip coating thickness on the front face wastargeted to 25 microns. The resulting die looks similar to FIG. 15except: (1) there is no current collector on the back face of 51 and 52,(2) anodic glass is 88, and (3) Glass powder with PVDF is 86.

Example 3 3D Single Cell Fabrication 3

1. Comb Structure Fabrication

The comb structure was fabricated similar to Example 2.

2. Negative Electrode Current Collector and Negative ElectrodeFabrication

The negative electrode current collector and negative electrodes werefabricated with a process similar to Example 1.

3. Positive Electrode Current Collector and Positive ElectrodeFabrication

The positive electrode current collector and positive electrodes werefabricated with a process similar to Example 1.

4. Separator Layer No. 1 Fabrication

A separator layer was fabricated with a process similar to Example 1.

5. Structural Layer Removal

The structural layer was removed by a process similar to Example 1.

6. Separator Layer No. 2 Fabrication

A second separator layer was fabricated with a process similar toExample 1 to yield an electrode structure of the type illustrated inFIG. 15.

Example 4 3D Single Cell Fabrication 4

1. Comb Structure Fabrication

The comb structure was fabricated similar to Example 2, except, theanodically bonded glass was a frame that was only contacting thenegative electrode and positive electrode combs at the top and bottomsof the die in the longitudinal axis and the contact pad areas. In otherwords, for the majority of the length along the longitudinal axis A_(E)in FIG. 4, the comb lines were designed to be freestanding. Saiddifferently, the majority of the back face of the die was accessible toprocessing as well.

2. Negative Electrode Current Collector and Negative ElectrodeFabrication

The negative electrode current collector and negative electrodes werefabricated with a process similar to Example 1.

3. Positive Electrode Current Collector and Positive ElectrodeFabrication

The positive electrode current collector and positive electrodes werefabricated with a process similar to Example 1.

4. Excess Positive Electrode and Negative Electrode Material Removal

Any excess positive electrode and negative electrode materials that weredeposited on the front and back face of the die were removed usingmechanical removal processes. The front face was lapped using apolishing pad to expose the current collector layers. A doctor bladeremoval process was performed on the back face to remove excesselectrode materials; followed by forced air drying to ensure no looseparticles that can cause shorts are present on the die.

5. Separator Fabrication

The porous separator is applied into the gap (which is nominally 40microns) between the positive electrode and the negative electrode, thefront face, and the back face, by using a slurry comprising fine glasspowder (<2 microns in diameter) dispersed in N-methylpyrollidone alongwith a PVDF binder of 2 volume percent with a solids content of 60% asmade. This slurry is screen printed so as to wet the die and force theparticulate matter to go in between the negative electrode and thepositive electrode materials. The screen printing is done in multiplepasses with an intermediate drying step in between so as to fill thetrenches between the negative electrode and positive electrode; and thegaps along the top and the bottom of the device (areas that constitute82 and 84 in FIG. 19). Once this is complete, additional layers areadded on to provide a separator layer covering the front and back facesof the die as well (see FIG. 3).

Example 5 3D Single Cell Fabrication 5

1. Comb Structure Fabrication

The comb structure was fabricated as in Example 4.

2. Negative Electrode Current Collector and Negative ElectrodeFabrication

The negative electrode current collector and negative electrodes werefabricated with a process similar to Example 1.

3. Positive Electrode Current Collector and Positive ElectrodeFabrication

The positive electrode current collector and Positive electrodes werefabricated with a process similar to Example 1.

4. Excess Positive Electrode and Negative Electrode Material Removal

The excess materials were removed with a process similar to Example 4.

5. Separator Fabrication

A commercially available electrically insulating two part epoxy wasdispensed with a syringe in order to fill up the top and bottom of thedie corresponding to items 82 and 84 in FIG. 19. This provides anon-porous, insulating separator layer between the electrode and itsopposing electrode bus.

The porous separator is subsequently applied into the gap (which isnominally 40 microns) between the positive electrode and the negativeelectrode, the front face, and the back face, by using a slurrycomprising fine glass powder (<2 microns in diameter) dispersed inN-methylpyrollidone along with a PVDF binder of 2 volume percent with asolids content of 60% as made. This slurry is screen printed so as towet the die and force the particulate matter to go in between thenegative electrode and the positive electrode materials. The screenprinting is done in multiple passes with an intermediate drying step inbetween so as to fill the trenches between the negative electrode andpositive electrode. Once this is complete, additional layers are addedon to provide a separator layer covering the front and back faces of thedie as well (see FIG. 3).

Example 6 3D Single Cell Fabrication 6

1. Comb Structure Fabrication

The comb structure was fabricated as in Example 4.

2. Negative Electrode Current Collector and Negative Electrode CurrentCollector Fabrication

The two current collectors are fabricated as in example 1; except thatthe positive electrode current collector was fabricated immediatelyafter the negative electrode current collector.

3. Separator Layer No. 1 Fabrication

A commercially available electrically insulating two part epoxy wasdispensed with a syringe in order to fill up the top and bottom of thedie corresponding to items 82 and 84 in FIG. 19. However, in this case,the epoxy is coats the negative electrode current collector and thepositive electrode current collector instead of the respectiveelectrodes as in Example 5. This provides a non-porous, insulatingseparator layer between the electrode and its opposing electrode bus.

4. Negative Electrode Fabrication, and Positive Electrode Fabrication

The negative electrodes and Positive electrodes were fabricated with aprocess similar to Example 4.

5. Excess Positive Electrode and Negative Electrode Removal

The excess materials were removed with a process similar to Example 4.

6. Separator Layer No. 2 Fabrication

A porous separator is subsequently applied into the gap (which isnominally 40 microns) between the positive electrode and the negativeelectrode, the front face, and the back face, by using a slurrycomprising fine glass powder (<2 microns in diameter) dispersed inN-methylpyrollidone along with a PVDF binder of 2 volume percent with asolids content of 60% as made. This slurry is screen printed so as towet the die and force the particulate matter to go in between thenegative electrode and the positive electrode materials. The screenprinting is done in multiple passes with an intermediate drying step inbetween so as to fill the trenches between the negative electrode andpositive electrode; and the gaps along the top and the bottom of thedevice (areas that constitute 82 and 84 in FIG. 19). Once this iscomplete, additional layers are added on to provide a separator layercovering the front and back faces of the die as well (See FIG. 3).

Example 7 3D Single Cell Fabrication 7

1. Comb Structure Fabrication

The comb structure was fabricated as in example 4; except the gapsbetween the negative electrode comb and the positive electrode comb werereduced to 80 microns instead of 100 microns. The negative electrodecomb layer was widened by 40 microns as well.

2. Negative Electrode and Negative Electrode Current CollectorFabrication

One of the isolated comb structures (herein named the positive electrodebackbone comb) was immersed in an electrophoretic resist bath. Acommercially available electrophoretic resist was used (Shipley EAGLE),and the positive electrode backbone comb was electrophoreticallydeposited at 50 V for 120 seconds using the Pd conductor to form aresist coating. The die was baked at 120 C for 30 min to harden theresist.

The silicon sample is now inserted into an evaporation chamber, and 100Å Au is deposited on the sample surface. This Au deposition processresults in Au on the top of the comb, its sidewalls, and on the bottomoxide layer. However, the photoresist being present on one of the combscauses the Au to be in contact with the silicon on only one of the twocomb structures. The silicon backing layer was also protected at thistime by an adhesive tape mask. This sample is subsequently immersed in asolution of 1:1 by volume of hydrofluoric acid (49%) and hydrogenperoxide (30%), at 30 C to form a porous silicon layer. The poroussilicon depth was tailored by varying the etching time. The approximaterate of formation of porous silicon was 750-1000 nm/min. The parts wereremoved and dried when a the target pore depth of 20 μm was reached.

The porous silicon is only formed on the comb-set that did not have theelectrophoretic resist patterned onto it. The porous silicon set is usedas the negative electrode in a lithium ion battery. The electrophoreticresist was subseqently stripped in acetone for 15 minutes.

The negative electrode backbone comb was subsequently electricallyconnected through the palladium conductor and was immersed in a copperplating bath consisting of very dilute (10 mM) copper sulfate andsulfuric acid. The copper plating bath conditions were adjusted suchthat the deposition happened both on the palladium and the poroussilicon. The copper concentration was kept low so that the copperdeposition was transport limited and porous along the outer layer of theporous silicon. This Cu layer will serve as the negative electrodecurrent collector that is also ionically permeable due to its porosity.The copper on the Pd layer, however, was thicker and non-porous to actas a secondary bussing collector for the negative electrode

3. Positive Electrode Current Collector and Positive ElectrodeFabrication

The positive electrode current collector and positive electrodes werefabricated with a process similar to Example 1.

4. Excess Positive Electrode and Negative Electrode Removal

The excess materials were removed with a process similar to Example 4.

5. Separator Fabrication

The porous separator is subsequently applied into the gap (which isnominally 40 microns) between the positive electrode and the negativeelectrode, the front face, and the back face, by using a slurrycomprising fine glass powder (<2 microns in diameter) dispersed inN-methylpyrollidone along with a PVDF binder of 2 volume percent with asolids content of 60% as made. This slurry is screen printed so as towet the die and force the particulate matter to go in between thenegative electrode and the positive electrode materials. The screenprinting is done in multiple passes with an intermediate drying step inbetween so as to fill the trenches between the negative electrode andpositive electrode; and the gaps along the top and the bottom of thedevice (areas that constitute 82 and 84 in FIG. 19). Once this iscomplete, additional layers are added on to provide a separator layercovering the front and back faces of the die as well (see FIG. 20).

Example 8 3D Single Cell Fabrication 8

1. Comb Structure Fabrication

The comb structure was fabricated as in example 4.

2. Negative Electrode and Negative Electrode Current CollectorFabrication

The negative electrode current collector was fabrication using a processsimilar to Example 1.

The negative electrode backbone comb was used to electrophoreticallydeposit graphite particles onto the comb surface using a non-aqueouselectrophoretic deposition slurry. The deposition slurry consisted ofgraphite particles (mesocarbon microbeads, 95% by weight) and carbonblack (5% by weight) dispersed in acetone with 25 ppm of iodine as thecharging agent. Electrophoretic deposition was done with a platinumcounter electrode at 100 V for 180 s to deposit a 60 micron average filmthickness.

Any excess negative electrode on the front and back face of the negativeelectrode comb was removed by mechanical grinding prior to proceeding tothe next step.

3. Separator Fabrication

A electrophoretic deposition slurry for aluminum oxide particles wasprepared as shown below. 3 wt % of sub-micron aluminum oxide particleswere added to an equivalent of 97 wt % of ethanol and stirred for 2hours. 0.05 wt % of polyvinyl butyral (calculated from the total weightof aluminum oxide and ethanol) was added to the above slurry.Hydrochloric acid was used to adjust the pH of the solution to 1.5. Theresultant mixture was stirred overnight.

The comb structure assembly was subsequently immersed thiselectrophoretic deposition bath and an electric field was appliedbetween the negative electrode comb and the positive electrode comb. TheAu plated positive electrode current collector comb served as thecounter electrode for the electrophoretic deposition process. Theworking electrode for the deposition of the separator was the negativeelectrode comb with the negative electrode on top The deposition currentwas kept constant at 2 mA/cm2 of current collector area; and the currentwas turned on for a period of 1800 seconds. This resulted in a 40 micronthick layer of aluminum oxide and polyvinyl butyral around theelectrophoretically deposited negative electrode.

4. Positive Electrode Current Collector Fabrication

The positive electrode current collector was fabricated with a processsimilar to Example 1.

5. Positive Electrode Fabrication

The die was subsequently coated with a slurry of a lithium ion positiveelectrode material of the following composition: Lithium Cobalt oxide 80g; graphite 5 g, carbon black 5 g, and PVDF 10 g; all mixed in N-MethylPyrollidone and acetone as the quick-drying solvent with a volume ratioof 1:2. The slurry was dried and the solvent was evaporated to leaveconductive positive electrode material behind. This material was thenlapped to the comb surface in order to expose the separator material onthe front and back faces of the samples.

Example 9 3D Battery Fabrication 1

1. Single Die Preparation

The contact pads that were used to process the dies in Examples 1-8 wereremoved by dicing using a dicing saw, while leaving the negativeelectrode and positive electrode bus connections intact. Any separatormaterial covering the edges of the dies and overhanging the bus lineswere cleaned out to remove and expose the current collector material, Cuin the case of the negative electrode and Au in case of the positiveelectrode.

2. Tab Extension Connection

Tab extensions were connected onto the negative electrode bus and thepositive electrode bus following the current collector exposure. Thegold bus line was connected to aluminum tab using a commerciallyavailable carbon glue (DAG-T-502). A thin layer of carbon was coated onthe tab extension and glued to the side of the gold bus. A Nickel tabextension was glued to the copper current collector bus using the samecommercially available carbon glue. The glue was baked at 120 C for 1 hrto harden. The tab extensions also included the tab that was to come outof the package. This tab extension was bent and flattened horizontallyand was ready for packaging.

3. Battery Packaging and Electrolyte Fill

The die with the two tab extensions was inserted into a commerciallyavailable battery pouch packaging material. The pouch material wassealed on the tab side through the tabs. One of the other three sideswas left open to provide aport for electrolyte filling. Vacuum wasapplied and a conventional electrolyte comprising propylene carbonate,ethylene carbonate, and ethyl methyl carbonate in a ratio of 1:1:3 and alithium hexafluorophosphate salt (1 M) was added to the cell while in aglove box. The last side of the pouch was also subsequently sealed whenthe die is inside the glove box in order to prevent moisture and oxygenfrom ingressing into the pouch and causing loss of battery life. Thebattery was then subsequently charge-discharged using a commerciallyavailable battery cycler.

Example 10 3D Stack Battery Fabrication 1

1. Single Die Preparation:

The Single die preparation process was performed identical to Example 5;except on three different dies separately. The contact pads on each ofthe dies were removed similar to example 9. The dies were subsequentlystacked one on top of other so that the electrodes were aligned.

2. Tab Extension Connection:

Tab extensions were connected onto the negative electrode buses and thepositive electrode buses following the current collector exposure. Thegold bus lines were connected to aluminum tab using a commerciallyavailable carbon glue (DAG-T-502). A thin layer of carbon was coated onthe tab extension and glued to the side of the gold bus. A Nickel tabextension was glued to the copper current collector buses using the samecommercially available carbon glue. The glue was baked at 120 C for 1 hrto harden. The tab extensions also included the tab that was to come outof the package. This tab extension was bent and flattened horizontallyand was ready for packaging.

3. Battery Packaging and Electrolyte Fill:

Battery Packaging and electrolyte fill was carried out as in Example 9

Example 11 3D Tiled Battery Fabrication 1

1. Single Die Preparation:

The Single die preparation process was performed identical to Example 5;except on two different dies separately

2. Tab Extension Connection:

The tab extension was connected with conductive glue similar to example9. However, the dies were tiled with the positive electrode busconnections abutting each other connected by a single tab extension inbetween.

3. Battery Packaging and Electrolyte Fill:

Battery Packaging and electrolyte fill was carried out as in Example 9

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

When introducing elements of the present invention or the preferredembodiments(s) thereof, the articles “a”, “an”, “the” and “said” areintended to mean that there are one or more of the elements. The terms“comprising”, “including” and “having” are intended to be inclusive andmean that there may be additional elements other than the listedelements.

As various changes could be made in the above articles, compositions andmethods without departing from the scope of the invention, it isintended that all matter contained in the above description and shown inthe accompanying drawings shall be interpreted as illustrative and notin a limiting sense.

What is claimed is:
 1. An electrode structure comprising a population ofelectrodes comprising an electrode active material layer and apopulation of counter-electrodes comprising a counter-electrode activematerial layer wherein the population of electrodes is arranged inalternating sequence with the population of counter-electrodes along afirst direction, each member of the electrode population has a bottom, atop, a length L_(E), a width W_(E), a height H_(E), and a longitudinalaxis A_(E) extending from the bottom to the top of each such member andin a direction that is transverse to the first direction, the lengthL_(E) of each member of the electrode population being measured in thedirection of its longitudinal axis A_(E), the width W_(E) of each memberof the electrode population being measured in the first direction, andthe height H_(E) of each member of the electrode population beingmeasured in a direction that is perpendicular to the longitudinal axisA_(E) of each such member and the first direction, the ratio of L_(E) toeach of W_(E) and H_(E) of each member of the electrode population beingat least 5:1, respectively, the ratio of H_(E) to W_(E) for each memberof the electrode population being between 0.4:1 and 1000:1,respectively, the longitudinal axis A_(E) of each member of thepopulation of electrodes is surrounded by an electrically insulatingseparator layer comprising a microporous separator material, such thatthe microporous separator material of the electrically insulatingseparator layer surrounds all surfaces of the member about thelongitudinal axis A_(E), and the microporous separator materialcomprises a particulate material and a binder, and has a void fractionof at least 20 vol %.
 2. The electrode structure of claim 1 whereinbetween members of the electrode population and members of thecounter-electrode population the microporous separator materialconstitutes at least 70 vol % of the electrically insulating separatormaterial layer.
 3. The electrode structure of claim 1 wherein themicroporous separator material surrounds the longitudinal axis A_(E) ofeach member of electrode population.
 4. The electrode structure of claim1 wherein the microporous separator material surrounds the longitudinalaxis A_(E) of each member of electrode population for at least 70% ofthe length L_(E) of each member of the electrode population.
 5. Theelectrode structure of claim 1 wherein the microporous separatormaterial surrounds the longitudinal axis A_(E) of each member ofelectrode population and the top of each member of the electrodepopulation.
 6. The electrode structure of claim 1 wherein theelectrically insulating separator layer comprises the microporousseparator material and a second electrically insulating material.
 7. Theelectrode structure of claim 1 wherein each of the electrode andcounter-electrode populations comprise at least 50 members.
 8. Theelectrode structure of claim 1 wherein L_(E) has a value in the range ofabout 10 mm and about 250 mm, W_(E) has a value in the range of about0.01 mm and 2.5 mm, and H_(E) has a value in the range of about 0.05 mmto about 10 mm.
 9. The electrode structure of claim 1 wherein the ratioof L_(E) to each of W_(E) and H_(E) for each member of the electrodepopulation is at least 10:1, respectively.
 10. The electrode structureof claim 1 wherein a cross-section of each member of the electrodepopulation has a perimeter P_(E) and the ratio of L_(E) to P_(E) foreach member of the electrode population is at least 1.25:1,respectively.
 11. The electrode structure of claim 1 wherein each memberof the counter-electrode population comprises a bottom, a top, a lengthL_(CE), a width W_(CE), a height H_(CE), and a longitudinal axis A_(CE)extending from the bottom to the top of each such member and in adirection that is transverse to the first direction, the length L_(CE)of each member of the electrode population being measured in thedirection of its longitudinal axis A_(CE), the width W_(CE) of eachmember of the electrode population being measured in the firstdirection, and the height H_(CE) of each member of the electrodepopulation being measured in a direction that is perpendicular to thelongitudinal axis A_(CE) of each such member and the first direction,the ratio of L_(CE) to each of W_(CE) and H_(CE) of each member of theelectrode population being at least 5:1, respectively, the ratio ofH_(CE) to W_(CE) for each member of the electrode population beingbetween 0.4:1 and 1000:1, respectively.
 12. The electrode structure ofclaim 11 wherein L_(CE) has a value in the range of about 10 mm andabout 250 mm, W_(CE) has a value in the range of about 0.01 mm and 2.5mm, and H_(CE) has a value in the range of about 0.05 mm to about 10 mm.13. The electrode structure of claim 11 wherein the ratio of L_(CE) toeach of W_(CE) and H_(CE) for each member of the electrode population isat least 10:1, respectively.
 14. The electrode structure of claim 1wherein a cross-section of each member of the counter-electrodepopulation has a perimeter P_(CE) and the ratio of L_(CE) to P_(CE) foreach member of the counter-electrode population is at least 1.25:1,respectively.
 15. The electrode structure of claim 1 wherein each memberof the population of electrodes further comprises an electrode backbone.16. The electrode structure of claim 15 wherein for each member of thepopulation of electrodes, the electrode current collector layercomprises an ionically permeable conductor material and is locatedbetween the electrode active material and the microporous separatormaterial and the electrode active material is between the electrodecurrent collector layer and the electrode backbone.
 17. The electrodestructure of claim 16 wherein for each member of the population ofelectrodes, the electrode current collector layer has an electricalconductance and an ionic conductance for carrier ions and the ratio ofthe electrical conductance of the electrode current collector layer tothe ionic conductance of the electrode current collector layer forcarrier ions is at least 1,000:1, respectively, when there is an appliedcurrent to store energy in the electrode structure or an applied load todischarge the electrode structure.
 18. The electrode structure of claim16 wherein the electrode current collector layer and the electrodeactive material layer have an electrical conductance and the ratio ofthe electrical conductance of the electrode current collector layer tothe electrical conductance of the electrode active material layer is atleast 100:1, respectively, for each member of the population ofelectrodes.
 19. The electrode structure of claim 1 wherein each memberof the population of electrodes further comprises a supplementalelectrode current collector layer having a length that is at least 60%of the length L_(E-C) of the electrode current collector layer comprisedby each such member and a conductance that is at least 200% of theconductance of the electrode current collector layer comprised by eachsuch member.
 20. The electrode structure electrode of claim 1 whereinthe electrode structure further comprises an electrode substrate havinga surface to which each member of the electrode population is directlyattached.
 21. The electrode structure of claim 1 wherein the electrodestructure further comprises an electrode substrate having a surface towhich each member of the electrode population is directly attached and acounter-electrode substrate having a surface to which each member of thecounter-electrode population is attached, the electrode substratesurface and the counter-electrode substrate surface being opposingsurfaces that are substantially parallel to the first direction.
 22. Theelectrode structure of claim 1 wherein the population of electrodes is apopulation of negative electrodes, the population of counter-electrodesis a population of positive electrodes, the electrode active materiallayer is a negative electrode active material layer and the electrodecurrent conductor layer is a negative electrode current conductor layer.23. The electrode structure of claim 22 wherein the negative electrodeactive material layer comprises carbon, aluminum, tin, silicon or analloy thereof.
 24. The electrode structure of claim 22 wherein thenegative electrode active material layer comprises nanowires of siliconor an alloy thereof, or porous silicon or an alloy thereof.
 25. Theelectrode structure of claim 1 wherein the population of electrodes is apopulation of negative electrodes, the population of counter-electrodesis a population of positive electrodes, each member of the population ofnegative electrodes comprises a negative electrode active material layerand a negative electrode current conductor layer, each member of thepopulation of negative electrodes has a bottom, a top, a length L_(NE),a width W_(NE) and a height H_(NE), the length L_(NE) being measuredfrom the bottom to the top of each such negative electrode, the widthW_(NE) and the height H_(NE) being measured in directions that areperpendicular to each other and to the direction of measurement of thelength L_(NE), the ratio of L_(NE) to each of W_(NE) and H_(NE) being atleast 5:1, respectively, the ratio of H_(NE) to W_(NE) being between0.4:1 and 1000:1, the negative electrode current collector layer of eachmember of the population having a length L_(NC) that is measured in thesame direction as and is at least 50% of L_(NE).
 26. The electrodestructure of claim 1 wherein the population of electrodes is apopulation of positive electrodes, the population of counter-electrodesis a population of negative electrodes, each member of the population ofpositive electrodes comprises a positive electrode active material layerand a positive electrode current conductor layer, each member of thepopulation of positive electrodes has a bottom, a top, a length L_(PE),a width W_(PE) and a height H_(PE), the length L_(PE) being measuredfrom the bottom to the top of each such positive electrode, the widthW_(PE) and the height H_(PE) being measured in directions that areperpendicular to each other and to the direction of measurement of thelength L_(PE), the ratio of L_(PE) to each of W_(PE) and H_(PE) being atleast 5:1, respectively, the ratio of H_(PE) to W_(PE) being between0.4:1 and 1000:1, respectively, the positive electrode current collectorlayer of each member of the positive population having a length Lpc thatis measured in the same direction as and is at least 50% of L_(PE). 27.An electrode stack, the stack comprising at least two electrodestructures, each of the electrode structures comprising an electrodestructure of claim
 1. 28. The electrode stack of claim 27 wherein theelectrode structures are stacked vertically whereby the populations ofpositive and negative electrodes comprised by a first electrodestructure in the electrode stack lie in a different plane than thepopulations of positive and negative electrodes comprised by a secondelectrode structure in the electrode stack.
 29. The electrode stack ofclaim 27 wherein the electrode structures are arranged horizontallywhereby the populations of positive and negative electrodes comprised bya first electrode structure in the electrode stack lie in substantiallythe same plane as the populations of positive and negative electrodescomprised by a second electrode structure in the electrode stack.
 30. Asecondary battery comprising a battery enclosure, a non-aqueouselectrolyte and an electrode structure of claim 1.